ORCID Profile
0000-0002-5341-5416
Current Organisations
Ministero dell'Istruzione dell'Università e della Ricerca
,
Ministero dell’Istruzione, dell’Università e della Ricerca
,
Garvan Institute of Medical Research
,
Royal Australasian College of Surgeons
,
Medical University of Vienna
,
Macquarie University
,
Macquarie University Hospital
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Neurocognitive Patterns and Neural Networks | Computer Vision | Artificial Intelligence and Image Processing | Computer Perception, Memory and Attention
Diagnostic Methods | Expanding Knowledge in Psychology and Cognitive Sciences | Application Tools and System Utilities |
Publisher: Elsevier BV
Date: 03-2011
DOI: 10.1016/J.MVR.2010.12.006
Abstract: There is currently no standard technique to objectively quantify the microvascularization of brain tumors. Fractal analysis has been proposed as a useful descriptor of tumor microvascularity. Standardization of the fractal analysis methodology could offer a new tool for this type of characterization. In this study, we applied fractal analysis to the characterization of the different angioarchitectures found in specimens of glioblastoma multiforme (GBM), the most common and most malignant type of human brain tumor. A retrospective series of 114 primary GBM specimens was carried out. To quantify neoplastic microvascularity, the level of two-dimensional geometrical complexity of the microvascular patterns was assessed using the box-counting algorithm, which estimates the microvascular fractal dimension (mvFD). mvFD makes information on the non-Euclidean space filled by vessels embedded in the tumor microenvironment available because it depends on vessel number, shape, magnitude and distribution pattern. A mean mvFD value of 1.44 ± 0.17 (range: 1.06-1.87) was found. The coefficient of variation was 44%. The high geometric variability, found objectively, in these s les reflects the angioarchitectural heterogeneity underlying GBM. The present study shows that angioarchitectural subtypes can be identified by mvFD, making this parameter a potential tool for quantifying different neoplastic microvascular patterns.
Publisher: Springer Science and Business Media LLC
Date: 08-03-2013
DOI: 10.1007/S00381-013-2061-4
Abstract: Progress in cranial suture research is shaping our current understanding of the topic however, emphasis has been placed on in idual contributing components rather than the cranial sutural system as a whole. Improving our holistic view helps further guide clinicians who treat cranial sutural abnormalities as well as researchers who study them. Information from anatomy, anthropology, surgery, and computed modeling was integrated to provide a perspective to interpret suture formation and variability within the cranial functional and structural system. Evidence from experimental settings, simulations, and evolution suggest a multifactorial morphogenetic process associated with functions and morphology of the sutures. Despite molecular influences, the biomechanical cranial environment has a main role in both the ontogenetic and phylogenetic suture dynamics. Furthering our holistic understanding of the intricate cranial sutural system promises to expand our knowledge and enhance our ability to treat associated anomalies.
Publisher: Archives of Pathology and Laboratory Medicine
Date: 29-11-2023
DOI: 10.5858/ARPA.2021-0518-OA
Abstract: Glioma is the most common primary brain tumor in adults. The diagnosis and grading of different pathological subtypes of glioma is essential in treatment planning and prognosis. To propose a deep learning–based approach for the automated classification of glioma histopathology images. Two classification methods, the ensemble method based on 2 binary classifiers and the multiclass method using a single multiclass classifier, were implemented to classify glioma images into astrocytoma, oligodendroglioma, and glioblastoma, according to the 5th edition of the World Health Organization classification of central nervous system tumors, published in 2021. We tested 2 different deep neural network architectures (VGG19 and ResNet50) and extensively validated the proposed approach based on The Cancer Genome Atlas data set (n = 700). We also studied the effects of stain normalization and data augmentation on the glioma classification task. With the binary classifiers, our model could distinguish astrocytoma and oligodendroglioma (combined) from glioblastoma with an accuracy of 0.917 (area under the curve [AUC] = 0.976) and astrocytoma from oligodendroglioma (accuracy = 0.821, AUC = 0.865). The multiclass method (accuracy = 0.861, AUC = 0.961) outperformed the ensemble method (accuracy = 0.847, AUC = 0.933) with the best performance displayed by the ResNet50 architecture. With the high performance of our model (& %), the proposed method can assist pathologists and physicians to support examination and differential diagnosis of glioma histopathology images, with the aim to expedite personalized medical care.
Publisher: Springer International Publishing
Date: 2021
Publisher: Springer Science and Business Media LLC
Date: 24-02-2022
DOI: 10.1007/S00234-022-02921-0
Abstract: To train deep learning convolutional neural network (CNN) models for classification of clinically significant Chiari malformation type I (CM1) on MRI to assist clinicians in diagnosis and decision making. A retrospective MRI dataset of patients diagnosed with CM1 and healthy in iduals with normal brain MRIs from the period January 2010 to May 2020 was used to train ResNet50 and VGG19 CNN models to automatically classify images as CM1 or normal. A total of 101 patients diagnosed with CM1 requiring surgery and 111 patients with normal brain MRIs were included (median age 30 with an interquartile range of 23–43 81 women with CM1). Isotropic volume transformation, image cropping, skull stripping, and data augmentation were employed to optimize model accuracy. K-fold cross validation was used to calculate sensitivity, specificity, and the area under receiver operating characteristic curve (AUC) for model evaluation. The VGG19 model with data augmentation achieved a sensitivity of 97.1% and a specificity of 97.4% with an AUC of 0.99. The ResNet50 model achieved a sensitivity of 94.0% and a specificity of 94.4% with an AUC of 0.98. VGG19 and ResNet50 CNN models can be trained to automatically detect clinically significant CM1 on MRI with a high sensitivity and specificity. These models have the potential to be developed into clinical support tools in diagnosing CM1.
Publisher: Elsevier BV
Date: 09-2010
DOI: 10.1016/J.MVR.2010.04.003
Abstract: Neuroradiological and metabolic imaging is a fundamental diagnostic procedure in the assessment of patients with primary and metastatic brain tumors. The correlation between objective parameters capable of quantifying the neoplastic angioarchitecture and imaging data may improve our understanding of the underlying physiopathology and make it possible to evaluate treatment efficacy in brain tumors. Only a few studies have so far correlated the quantitative parameters measuring the neovascularity of brain tumors with the metabolic profiles measured by means of amino acid uptake in positron emission tomography (PET) scans. Fractal geometry offers new mathematical tools for the description and quantification of complex anatomical systems, including microvascularity. In this study, we evaluated the microvascular network complexity of six cases of human glioblastoma multiforme quantifying the surface fractal dimension on CD34 immunostained specimens. The microvascular fractal dimension was estimated by applying the box-counting algorithm. As the fractal dimension depends on the density, size and shape of the vessels, and their distribution pattern, we defined it as an index of the whole complexity of microvascular architecture and compared it with the uptake of (11)C-methionine (MET) assessed by PET. The different fractal dimension values observed showed that the same histological category of brain tumor had different microvascular network architectures. Fractal dimension ranged between 1.19 and 1.77 (mean: 1.415+/-0.225), and the uptake of (11)C-methionine ranged between 1.30 and 5.30. A statistically significant direct correlation between the microvascular fractal dimension and the uptake of (11)C-methionine (p=0.02) was found. Our preliminary findings indicate that that vascularity (estimated on the histologic specimens by means of the fractal dimension) and (11)C-methionine uptake (assessed by PET) closely correlate in glioblastoma multiforme and that microvascular fractal dimension can be a useful parameter to objectively describe and quantify the geometrical complexity of the microangioarchitecture in glioblastoma multiforme.
Publisher: Springer Science and Business Media LLC
Date: 05-05-2007
DOI: 10.1007/S10143-007-0079-3
Abstract: Granular cell astrocytomas are uncommon tumors of the central nervous system (CNS) of which no cases have been documented in the spinal cord. This variant of glioma should not be confused with benign granular cell tumor which, although rare, has been well characterized in the spinal cord. We describe here the clinical, pathological, and radiological features of such an astrocytoma arising within the spinal cord at the dorsal level. A 48-year-old female was seen after about 1 year of dorsal pain and gradual spastic paraparesis. Magnetic resonance imaging (MRI) studies showed a 2-cm contrast-enhanced mass in the spinal cord at T6-T7, which had the appearance of an astrocytoma. At surgery, the tumor was found to be infiltrating a posterior column with no dural attachment. It was debulked and dissected. The histological diagnosis was astrocytoma with granular cell differentiation. In addition to documenting a unique ex le of intramedullary granular cell astrocytoma, we review the literature to investigate differences from other tumors with granular changes described in the spinal cord.
Publisher: Springer New York
Date: 2016
Publisher: American Society of Neuroradiology (ASNR)
Date: 12-04-2012
DOI: 10.3174/AJNR.A3085
Publisher: SAGE Publications
Date: 12-2010
Abstract: In the history of medicine, the understanding of the nervous system, both from an anatomical and a functional point of view, has always required new and more sophisticated tools. It has been widely demonstrated that engineering has helped towards this end. Incorporation of improved technical tools has expanded the available armamentarium to perform neurological surgery. Neurosurgery probably presents the most major challenges and always benefits from the introduction of sophisticated tools, from cranial trephination to the most modern robotics. This review examines the role of engineering to assist in neurosurgery.
Publisher: Informa UK Limited
Date: 22-05-2014
DOI: 10.1586/17446651.2014.922412
Abstract: Pituitary adenomas are common tumors arising in adenohypophysial cells or their precursors. For improving control of the disease an early diagnosis is important. Initially considered sporadic tumors, some of them are associated with familial syndromes and their recognition and classification is also required. Morphologically, pituitary adenomas represent a heterogeneous group of tumors with several subtypes and different clinical behavior thus a precise pathological diagnosis is crucial. The simple diagnosis of pituitary adenoma is not satisfactory and the correct classification of histological subtypes may predict aggressiveness in the majority of cases. Although considered not malignant, some of them are clinically aggressive and their recognition remains a challenge. In this paper we present the recent advances in the event of improving early recognition and differential diagnosis of pituitary tumors.
Publisher: Springer Science and Business Media LLC
Date: 15-12-2012
DOI: 10.1007/S10143-011-0371-0
Abstract: The telovelar approach allows reliable access to the fourth ventricle and avoids the splitting of the vermis and its associated "posterior vermal split syndrome." Our objective was to describe the endoscopic topographical anatomy of the telovelum approach to the fourth ventricle as accessed by the cerebellomedullary corridor. A series of 20 fresh and fixed injected anatomical specimens were used. The endoscopic equipment consisted of rigid endoscopes with different lens angles, while the extradural step required the use of the microscope and/or the exoscope. All the anatomical landmarks and relationships within the fourth ventricle and the cerebellomedullary fissure were identified by means of the endoscopic microscope/exoscope-assisted telovelar approach. In conclusion, we showed that the endoscope is a valid tool to gain an anatomic understanding of the fourth ventricle reached by means of the telovelar approach.
Publisher: Wiley
Date: 09-08-2023
Abstract: Combination drug therapy addresses the auxiliary cancer pathways of the tumor progression unaffected by the standard adjuvant treatments such as radio‐ and chemotherapy. It is a particularly attractive strategy to improve the treatment outcomes and the quality of life in patients with the deadliest brain cancer, glioblastoma (GB). Testing of combination drug treatment protocols requires reliable, efficient, and biologically accurate preclinical testbeds applicable before the transition to clinical trials. The 3D in vitro models of GB are a promising platform for pharmacological research. However, there is notable methodological uncertainty and a highly scattered data landscape regarding drug testing in 3D in vitro models of GB. In particular, it is not completely clear how to mimic clinically relevant dozing and schedule of the main chemotherapy drug for GB, temozolomide (TMZ) in 3D in vitro GB models. Here, the authors carefully explore the available literature on the application of TMZ in 3D in vitro models of GB, both as a sole agent and in combination with other medications. The joint analysis of the tumor modeling approaches, the employed assays, and the obtained treatment responses provided in this review may be used as a roadmap for future research in combination treatments of GB.
Publisher: Elsevier BV
Date: 11-2022
DOI: 10.1016/J.MEDIA.2022.102580
Abstract: Deep learning has shown its effectiveness in histopathology image analysis, such as pathology detection and classification. However, stain colour variation in Hematoxylin and Eosin (H&E) stained histopathology images poses challenges in effectively training deep learning-based algorithms. To alleviate this problem, stain normalisation methods have been proposed, with most of the recent methods utilising generative adversarial networks (GAN). However, these methods are either trained fully with paired images from the target domain (supervised) or with unpaired images (unsupervised), suffering from either large discrepancy between domains or risks of undertrained/overfitted models when only the target domain images are used for training. In this paper, we introduce a colour adaptive generative network (CAGAN) for stain normalisation which combines both supervised learning from target domain and unsupervised learning from source domain. Specifically, we propose a dual-decoder generator and force consistency between their outputs thus introducing extra supervision which benefits from extra training with source domain images. Moreover, our model is immutable to stain colour variations due to the use of stain colour augmentation. We further implement histogram loss to ensure the processed images are coloured with the target domain colours regardless of their content differences. Extensive experiments on four public histopathology image datasets including TCGA-IDH, CAMELYON16, CAMELYON17 and BreakHis demonstrate that our proposed method produces high quality stain normalised images which improve the performance of benchmark algorithms by 5% to 10% compared to baselines not using normalisation.
Publisher: Springer International Publishing
Date: 04-12-2022
DOI: 10.1007/978-3-030-85292-4_22
Abstract: The heterogeneity of brain tumours at the molecular, metabolic and structural levels poses significant challenge for accurate tissue characterisation. Artificial intelligence and radiomics have emerged as valuable tools to analyse quantitative features extracted from medical images which capture the complex microenvironment of brain tumours. In particular, a number of computational tools including machine learning algorithms have been proposed for image preprocessing, tumour segmentation, feature extraction, classification, and prognostic stratifications as well. In this chapter, we explore the fundamentals of multiparametric brain tumour characterisation, as an understanding of the strengths, limitations and applications of these tools allows clinicians to better develop and evaluate models with improved diagnostic and prognostic value in brain tumour patients.
Publisher: Frontiers Media SA
Date: 12-06-2015
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2008
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2007
Publisher: Springer Science and Business Media LLC
Date: 27-09-2011
DOI: 10.1007/S10143-011-0352-3
Abstract: Detailed outcome data for the management of anterior skull base fractures associated with cerebrospinal fluid (CSF) leakage is lacking. We present detailed follow-up data of a single-center study using a predetermined algorithm for the management of CSF leakage secondary to traumatic fractures. A number of 138 consecutive patients were included in the analysis all patients underwent high-resolution computed tomography (CT) scanning at time of admission with β(2)-transferrin testing used to confirm CSF leakage. Patients with acute surgical indications were operated as emergent leaks were repaired at the time of initial surgery in patients with intracranial pressure < 15 cm H(2)O. The remainder of the study population was managed conservatively including use of prophylactic antibiotics lumbar drainage (LD) catheters were placed in those patients with leakage persisting beyond 48 h. Leaks lasting longer than 5 days underwent microsurgical repair using an intradural bicoronal approach. One-year follow-up assessment included evaluation of neurological status, Glasgow Outcome Scale (GOS), and repeat head CT. Twenty eight patients (26.9%) underwent emergent surgery, 15 of whom had simultaneous CSF leak repair, whereas 76 patients (73.1%) underwent delayed CSF leak repair between days 5 and 14. Postoperative meningitis rate was low (1.9%). Postoperative CSF leak (1.9%) was managed by intradural or transnasal endoscopic operation. Comparable rates of anosmia and frontal lobe hypodensities were seen in the surgical and conservatively managed subgroups. The presented algorithm, utilizing prophylactic antibiotics, trial of LD, acute and/or delayed intradural microsurgery, yields favorable outcomes. Large randomized controlled trials are needed to better define the role of prophylactic antibiotics and to better characterize the optimal timing and approach of surgical repair.
Publisher: Elsevier BV
Date: 10-2020
Publisher: Springer Science and Business Media LLC
Date: 08-03-2008
DOI: 10.1007/S10143-008-0127-7
Abstract: In geometrical terms, tumour vascularity is an exemplary anatomical system that irregularly fills a three-dimensional Euclidean space. This physical characteristic and the highly variable shapes of the vessels lead to considerable spatial and temporal heterogeneity in the delivery of oxygen, nutrients and drugs, and the removal of metabolites. Although these biological characteristics are well known, quantitative analyses of newly formed vessels in two-dimensional histological sections still fail to view their architecture as a non-Euclidean geometrical entity, thus leading to errors in visual interpretation and discordant results from different laboratories concerning the same tumour. We here review the literature concerning microvessel density estimates (a Euclidean-based approach quantifying vascularity in normal and neoplastic pituitary tissues) and compare the results. We also discuss the limitations of Euclidean quantitative analyses of vascularity and the helpfulness of a fractal geometry-based approach as a better means of quantifying normal and neoplastic pituitary microvasculature.
Publisher: Elsevier BV
Date: 2011
DOI: 10.1016/J.NEUROIMAGE.2010.07.045
Abstract: The veins of the dentate nucleus are composed of several channels draining the external surface and one single vein draining the internal surface. We analyzed specimens of the human cerebellum and described the central vein of the nucleus dentatus as the main venous outflow of the nucleus. The central vein of the nucleus dentatus is formed by a network of smaller vessels draining the sinuosities of the gray matter it emerges from the hilum of the nucleus and runs along the superior cerebellar peduncle, opening in the anterior vermian vein. We looked for this structure and for the surrounding veins on ultra-high-field (7 Tesla) MR, using susceptibility-weighted imaging. An anatomical and radiological description of the veins of the dentate nucleus is provided, with some remarks on the future clinical applications that these findings could provide.
Publisher: Elsevier BV
Date: 09-2015
DOI: 10.1016/J.PRP.2015.04.005
Abstract: Primary or metastatic melanocytic tumors in the sellar region are rare and can pose a diagnostic challenge. Here we describe a case of a 74-year-old man who underwent radiological investigations for a transient episode of blurred vision. Based on the clinical and endocrinological findings and MRI results, the patient was assumed to have a clinically non-functioning pituitary macroadenoma, which was followed-up over a 2-year period. He did not have any endocrine symptoms or progressive visual deterioration, and no history of past malignancy, including melanoma. Endocrinological investigation was unremarkable blood hormone levels were within the normal ranges except for low serum total testosterone and bioavailable testosterone levels without symptoms of hypogonadism. The longitudinal MRI follow-up demonstrated a gradual increase in the size of the tumor over the course of 11 months. For this reason, the patient underwent surgery. Pathologic examination including histology, immunohistochemistry and electron microscopy achieved the correct diagnosis of melanocytic tumor of the sellar region morphologic examination is essential in the diagnosis of melanocytic tumors. Hmb-45 is an important diagnostic biomarker in melanocytic lesions. The use and exploration of miRNA, Ki67 and osteopontin are important in understanding the genesis, progression, and prognosis in treatment of patients with melanocytic tumors.
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.EJRAD.2019.08.003
Abstract: Glioblastomas (GBM) and metastases are the most frequent malignant brain tumors in the adult population. Their presentation on conventional MRI is quite similar, but treatment strategy and prognosis are substantially different. Even with advanced MR techniques, in some cases diagnostic uncertainty remains. The main objective of this study was to determine whether fractal, texture, or both MR image analyses could aid in differentiating glioblastoma from solitary brain metastasis. In a retrospective study of 55 patients (30 glioblastomas and 25 solitary metastases) who underwent T2W/SWI/CET1 MRI, quantitative parameters of fractal and texture analysis were estimated, using box-counting and gray level co-occurrence matrix (GLCM) methods. All five GLCM parameters obtained from T2W images showed significant difference between glioblastomas and solitary metastases, as well as on CET1 images except correlation (S Computational-aided quantitative image analysis may potentially improve diagnostic accuracy. According to our results texture features are more significant than fractal-based features in differentiation glioblastoma from solitary metastasis.
Publisher: JMIR Publications Inc.
Date: 02-05-2020
Abstract: he radiological differential diagnosis between tumor recurrence and radiation-induced necrosis (ie, pseudoprogression) is of paramount importance in the management of glioma patients. his research aims to develop a deep learning methodology for automated differentiation of tumor recurrence from radiation necrosis based on routine magnetic resonance imaging (MRI) scans. n this retrospective study, 146 patients who underwent radiation therapy after glioma resection and presented with suspected recurrent lesions at the follow-up MRI examination were selected for analysis. Routine MRI scans were acquired from each patient, including T1, T2, and gadolinium-contrast-enhanced T1 sequences. Of those cases, 96 (65.8%) were confirmed as glioma recurrence on postsurgical pathological examination, while 50 (34.2%) were diagnosed as necrosis. A light-weighted deep neural network (DNN) (ie, efficient radionecrosis neural network [ERN-Net]) was proposed to learn radiological features of gliomas and necrosis from MRI scans. Sensitivity, specificity, accuracy, and area under the curve (AUC) were used to evaluate performance of the model in both image-wise and subject-wise classifications. Preoperative diagnostic performance of the model was also compared to that of the state-of-the-art DNN models and five experienced neurosurgeons. NN models based on multimodal MRI outperformed single-modal models. ERN-Net achieved the highest AUC in both image-wise (0.915) and subject-wise (0.958) classification tasks. The evaluated DNN models achieved an average sensitivity of 0.947 (SD 0.033), specificity of 0.817 (SD 0.075), and accuracy of 0.903 (SD 0.026), which were significantly better than the tested neurosurgeons ( i P /i =.02 in sensitivity and i P /i & .001 in specificity and accuracy). eep learning offers a useful computational tool for the differential diagnosis between recurrent gliomas and necrosis. The proposed ERN-Net model, a simple and effective DNN model, achieved excellent performance on routine MRI scans and showed a high clinical applicability.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2015
Publisher: Springer Science and Business Media LLC
Date: 13-05-2014
Abstract: The WHO categorizes pituitary tumours as typical adenomas, atypical adenomas and pituitary carcinomas, with typical adenomas constituting the major class. However, the WHO classification does not provide an accurate correlation between histopathological findings and clinical behaviour. Tumours lacking typical histological features are classified as atypical, but not all are clinically atypical or exhibit aggressive behaviour. Pituitary carcinomas, by definition, have craniospinal or systemic metastases, although not all display classical cytological features of malignancy. Aggressive pituitary adenomas, defined from a clinical perspective, have earlier and more frequent recurrences and can be resistant to conventional treatments. Specific biomarkers have not yet been identified that can distinguish between clinically aggressive and nonaggressive pituitary adenomas, although the antigen Ki-67 proliferation index might be of value. This Review highlights the need to develop new biomarkers to facilitate the early detection of clinically aggressive pituitary adenomas and discusses emerging markers that hold promise for their identification. Defining aggressiveness is of crucial importance for improving the management of patients by enhancing prognostic predictions and effectiveness of treatment. New drugs, such as temozolomide, have potential use in the management of these patients anti-VEGF therapy, mTOR and tyrosine kinase inhibitors are also potentially useful in managing selected patients.
Publisher: Journal of Neurosurgery Publishing Group (JNSPG)
Date: 09-2010
Publisher: Frontiers Media SA
Date: 25-11-2016
Publisher: IEEE
Date: 06-2014
Publisher: Elsevier BV
Date: 08-2019
DOI: 10.1016/J.WNEU.2019.05.036
Abstract: The nomenclature of the 12 cranial nerves as we know it today was developed over a series of anatomic findings by some of history's most famous anatomists from Galen to Von Soemmerring. In this paper, we review the literature to present an overview of the remarkable historical journey that brought our forefathers to trace the pathway of in idual cranial nerves from origin to destination. In particular, we discuss the evolution of the naming of the cranial nerves and highlight relevant eponymous descriptions. We also include some poignant illustrations of cranial nerves by ancient anatomists that set the scene to their discoveries. In reviewing this legacy, we summarize the important product of centuries of discoveries and investigations and the limitations of cranial nerve classification systems.
Publisher: Springer Science and Business Media LLC
Date: 14-12-2015
DOI: 10.1007/S11102-014-0619-0
Abstract: Managing Cushing's disease remains a challenge. Surgery is the first option of treatment and it offers a high success rate. Even in cases where biochemical remission is not achieved, it is crucial to obtain surgical tissue for morphological diagnosis because the therapeutic approach can be modified according to the findings. A literature search was performed using PubMed for information regarding pathology and Cushing's disease. The histopathological features found in the pituitary gland of patients with Cushing's disease are presented. Different subtypes of ACTH-producing pituitary tumors are recognized and characterized. The significance of finding a normal pituitary gland with or without Crooke's changes is also discussed.
Publisher: Springer Science and Business Media LLC
Date: 13-01-2017
DOI: 10.1007/S12253-017-0196-4
Abstract: The term "vasculogenic mimicry" (VM) refers to the phenomenon in which vascular-like channels, which are not lined by endothelial cells, are formed in tumors. Since its discovery in 1999, it has been observed in several tumor types and is proposed to provide blood perfusion to tumors in absence of co-apted or neo-angiogenic blood vessels. Pituitary tumors are generally slow growing, benign adenomas which are less vascularized than the normal pituitary gland. To date, VM in pituitary adenomas has not been described. In this histological study, we assessed the presence of VM in a series of surgically resected clinically non-functioning pituitary adenomas (NFPAs) using CD34 and Periodic Acid-Schiff (PAS) double staining. To identify VM, slides were assessed for the presence of CD34-negative and PAS-positive channels indicating that they were not lined by endothelial cells. The histological staining pattern suggestive of VM was noted in 22/49 (44.9%) of the specimens studied. VM was observed in both recurring and non-recurring NFPAs. The incidence of VM present varied from case to case and within groups. There was no association between the presence of VM and gender, tumor size, Ki-67 index, recurrence or cavernous sinus invasion. VM was not noted in cases of non-tumorous pituitaries. Our findings suggest the existence of a complementary perfusion system in pituitary adenomas, implying potential clinical implications with respect to response to therapy and clinical course. Further research is warranted to confirm the presence of VM in pituitary adenomas to elucidate its clinical relevance in patients diagnosed with a pituitary adenoma.
Publisher: Frontiers Media SA
Date: 11-09-2015
Publisher: Informa UK Limited
Date: 26-05-2017
Publisher: Springer Science and Business Media LLC
Date: 02-11-2022
DOI: 10.1007/S11517-021-02464-1
Abstract: Magnetic Resonance Imaging (MRI) is used in everyday clinical practice to assess brain tumors. Deep Convolutional Neural Networks (DCNN) have recently shown very promising results in brain tumor segmentation tasks however, DCNN models fail the task when applied to volumes that are different from the training dataset. One of the reasons is due to the lack of data standardization to adjust for different models and MR machines. In this work, a 3D spherical coordinates transform during the pre-processing phase has been hypothesized to improve DCNN models' accuracy and to allow more generalizable results even when the model is trained on small and heterogeneous datasets and translated into different domains. Indeed, the spherical coordinate system avoids several standardization issues since it works independently of resolution and imaging settings. The model trained on spherical transform pre-processed inputs resulted in superior performance over the Cartesian-input trained model on predicting gliomas' segmentation on Tumor Core and Enhancing Tumor classes, achieving a further improvement in accuracy by merging the two models together. The proposed model is not resolution-dependent, thus improving segmentation accuracy and theoretically solving some transfer learning problems related to the domain shifting, at least in terms of image resolution in the datasets.
Publisher: Journal of Neurosurgery Publishing Group (JNSPG)
Date: 10-2012
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-04-2021
Publisher: Springer Science and Business Media LLC
Date: 07-05-2020
DOI: 10.1038/S41598-020-64588-Y
Abstract: Mutations in isocitrate dehydrogenase genes IDH1 and IDH2 are frequently found in diffuse and anaplastic astrocytic and oligodendroglial tumours as well as in secondary glioblastomas. As IDH is a very important prognostic, diagnostic and therapeutic biomarker for glioma, it is of paramount importance to determine its mutational status. The haematoxylin and eosin (H& E) staining is a valuable tool in precision oncology as it guides histopathology-based diagnosis and proceeding patient’s treatment. However, H& E staining alone does not determine the IDH mutational status of a tumour. Deep learning methods applied to MRI data have been demonstrated to be a useful tool in IDH status prediction, however the effectiveness of deep learning on H& E slides in the clinical setting has not been investigated so far. Furthermore, the performance of deep learning methods in medical imaging has been practically limited by small s le sizes currently available. Here we propose a data augmentation method based on the Generative Adversarial Networks (GAN) deep learning methodology, to improve the prediction performance of IDH mutational status using H& E slides. The H& E slides were acquired from 266 grade II-IV glioma patients from a mixture of public and private databases, including 130 IDH-wildtype and 136 IDH-mutant patients. A baseline deep learning model without data augmentation achieved an accuracy of 0.794 (AUC = 0.920). With GAN-based data augmentation, the accuracy of the IDH mutational status prediction was improved to 0.853 (AUC = 0.927) when the 3,000 GAN generated training s les were added to the original training set (24,000 s les). By integrating also patients’ age into the model, the accuracy improved further to 0.882 (AUC = 0.931). Our findings show that deep learning methodology, enhanced by GAN data augmentation, can support physicians in gliomas’ IDH status prediction.
Publisher: Wiley
Date: 06-11-2014
DOI: 10.1111/NEUP.12174
Abstract: Chordoid meningioma (CM) is a rare subtype of meningioma, classified as grade II, which exhibits a high rate of recurrence following subtotal resection. We retrospectively examined nine cases of chordoid meningioma over a case series of 1743 meningiomas (0.52%) operated upon at our institution from 1995 to 2013. All the reported clinicopathological findings were analyzed. Two hundred and twenty-one CM cases have been published to date worldwide and few single-center large case series have been issued. Seventy-five percent of the cases that underwent subtotal resection at our institution had recurrence within 1 year. Total resection of the tumor should be the major objective of surgery to reduce the possibility of tumor recurrence. The percentage of chordoid features within the tumor specimen could assist in predicting the pathogenesis of the lesion. The correlation of the index of proliferation to recurrence rate is still controversial. Much debate exists with regard to the role of adjuvant radiotherapy in CM cases. Immunohistochemical, cytological and ultrastructural studies should be used in combination to assure a correct diagnosis of CM. Owing to the rare occurrence of this meningioma subtype, larger case series are required to assist in providing a reference for diagnosis and to improve the therapeutic management of CM.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2013
Publisher: Springer Science and Business Media LLC
Date: 15-03-2013
DOI: 10.1007/S00701-013-1677-1
Abstract: The binasal fully endoscopic transphenoidal approach in skull base surgery requires a specific learning curve and expertise and, even in the hands of experienced surgeons, can be challenging. Quick and efficient endoscopic access can be impeded by factors like a deviated nasal septum and/or very narrow nasal cavity. For this reason, we developed a simple technique to facilitate rapid maneuvering of the endoscope in and out of the nose in the case of a narrow surgical corridor. Using a canula in situ in one of the nostrils, the endoscope can be maneuvered in and out of the nose to rapidly reach the surgical target without inadvertent mucosal trauma that can cause bleeding. This technique is very simple and is particularly helpful for novice neuroendoscopists who are trying to navigate the confines of a narrow nasal cavity, especially when they are assisting more experienced colleagues.
Publisher: Springer Science and Business Media LLC
Date: 29-05-2012
DOI: 10.1038/SREP00429
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2014
Publisher: Frontiers Media SA
Date: 2011
Publisher: Springer New York
Date: 2016
Publisher: Springer New York
Date: 2016
Publisher: Frontiers Media SA
Date: 24-06-2016
Publisher: SAGE Publications
Date: 20-12-2013
Abstract: It has been ascertained that the human brain is a complex system studied at multiple scales, from neurons and microcircuits to macronetworks. The brain is characterized by a hierarchical organization that gives rise to its highly topological and functional complexity. Over the last decades, fractal geometry has been shown as a universal tool for the analysis and quantification of the geometric complexity of natural objects, including the brain. The fractal dimension has been identified as a quantitative parameter for the evaluation of the roughness of neural structures, the estimation of time series, and the description of patterns, thus able to discriminate different states of the brain in its entire physiopathological spectrum. Fractal-based computational analyses have been applied to the neurosciences, particularly in the field of clinical neurosciences including neuroimaging and neuroradiology, neurology and neurosurgery, psychiatry and psychology, and neuro-oncology and neuropathology. After a review of the basic concepts of fractal analysis and its main applications to the basic neurosciences in part I of this series, here, we review the main applications of fractals to the clinical neurosciences for a holistic approach towards a fractal geometry model of the brain.
Publisher: SAGE Publications
Date: 20-12-2013
Abstract: The natural complexity of the brain, its hierarchical structure, and the sophisticated topological architecture of the neurons organized in micronetworks and macronetworks are all factors contributing to the limits of the application of Euclidean geometry and linear dynamics to the neurosciences. The introduction of fractal geometry for the quantitative analysis and description of the geometric complexity of natural systems has been a major paradigm shift in the last decades. Nowadays, modern neurosciences admit the prevalence of fractal properties such as self-similarity in the brain at various levels of observation, from the microscale to the macroscale, in molecular, anatomic, functional, and pathological perspectives. Fractal geometry is a mathematical model that offers a universal language for the quantitative description of neurons and glial cells as well as the brain as a whole, with its complex three-dimensional structure, in all its physiopathological spectrums. For a holistic view of fractal geometry of the brain, we review here the basic concepts of fractal analysis and its main applications to the basic neurosciences.
Publisher: Springer Science and Business Media LLC
Date: 29-11-2013
DOI: 10.1007/S10143-012-0433-Y
Abstract: Minimally invasive surgery to the posterolateral craniovertebral junction (CVJ) has not been sufficiently described. The aims of this study were to evaluate the feasibility of an endoscopic far-lateral approach to the posterolateral craniocervical junction and to better understand the related anatomy under distorted endoscopic view. Ten fresh cadavers were studied with 4-mm 0° and 30° endoscopes to develop the surgical approach and to identify surgical landmarks. After making a 3-cm straight incision behind the mastoid process, the superior oblique and rectus capitis posterior major muscles were partially exposed. An endoscope was then introduced and the two muscles were followed inferiorly until the posterior arch of the atlas appeared. The two muscles were removed to create le working space without violating the posterior atlanto-occipital membrane. The vertebral artery was identified by the landmark of the posterior arch of the atlas, and the atlanto-occipital joint and foramen magnum were exposed. In addition to suboccipital craniectomy, transcondylar, supracondylar, and paracondylar extension by drilling were applicable through the narrow corridor under superb visualization. The intradural neurovascular structures from the acousticofacial bundle to the dorsal root of C2, anterolateral space of the foramen magnum, cerebellomedullary fissure, and fourth ventricle were clearly demonstrated. This endoscopic far-lateral approach offers excellent exposure of surgical landmarks around the posterolateral CVJ with minimal invasiveness. Endoscopic soft tissue dissection is key to creating the surgical corridor. This approach could offer an alternative to the conventional far-lateral approach in selected cases.
Publisher: Dustri-Verlgag Dr. Karl Feistle
Date: 09-2012
DOI: 10.5414/NP300485
Abstract: Brain tumors are characterized by a microvascular network which differs from normal brain vascularity. Different tumors show in idual angiogenic patterns. Microvascular heterogeneity can also be observed within a neoplastic histotype. It has been shown that quantification of neoplastic microvascular patterns could be used in combination with the histological grade for tumor characterization and to refine clinical prognoses, even if no objective parameters have yet been validated. To overcome the limits of the Euclidean approach, we employ fractal geometry to analyze the geometric complexity underlying the microangioarchitectural networks in brain tumors. We have developed a computer-aided fractal-based analysis for the quantification of the microvascular patterns in histological specimens and ultra-high-field (7-Tesla) magnetic resonance images. We demonstrate that the fractal parameters are valid estimators of microvascular geometrical complexity. Furthermore, our analysis allows us to demonstrate the high geometrical variability underlying the angioarchitecture of glioblastoma multiforme and to differentiate low-grade from malignant tumors in histological specimens and radiological images. Based on the results of this study, we speculate the existence of a gradient in the geometrical complexity of microvascular networks from those in the normal brain to those in malignant brain tumors. Here, we summarize a new methodology for the application of fractal analysis to the study of the microangioarchitecture of brain tumors we further suggest this approach as a tool for quantifying and categorizing different neoplastic microvascular patterns and as a potential morphometric biomarker for use in clinical practice.
Publisher: Elsevier BV
Date: 2021
Publisher: Georg Thieme Verlag KG
Date: 16-05-2014
Abstract: To avoid cerebrospinal fluid leaks and related possible complications, the dura mater should be meticulously closed after craniotomy procedures. Several techniques for duraplasty and different material for watertight closure have been described. To describe a device to be used for the training of neurosurgical procedures of duraplasty. A plastic dummy with a balloon was developed to test the efficacy of the watertight closure of the dura. The technical notes to reproduce the method have been described. The described model represents a new, simple, effective and affordable device to be used for neurosurgical training in the procedures of duraplasty and to test the efficacy of watertight closures.
Publisher: Springer New York
Date: 2016
Publisher: Springer New York
Date: 2016
Publisher: Springer Science and Business Media LLC
Date: 23-10-2015
Publisher: Georg Thieme Verlag KG
Date: 21-12-2010
Abstract: The term arachnoiditis describes the inflammation of the meninges and subarachnoid spaces. Lumbar arachnoiditis is characterized by obliterated nerve root sleeves and the adherence of nerve roots to each other in the proximity of the cauda equina, and may be secondary to infectious diseases or tumors, iatrogenic (subsequent to spinal surgery) or idiopathic. It is not very clearly defined epidemiologically or clinically, and various theories regarding its pathophysiology have been proposed furthermore, its treatment is difficult because there is a lack of evidence-based diagnostic and therapeutic gold standards. Thecaloscopy has been recently described as a novel technique for retrograde transcutaneous neuroendoscopic inspection of the subarachnoid structures of the lumbar thecal sac it has also been suggested for the treatment of lumbar arachnoiditis. We here review the most modern techniques for the treatment of this disease such as thecaloscopy and neurostimulation.
Publisher: Oxford University Press (OUP)
Date: 26-10-2023
DOI: 10.1093/NOP/NPAC083
Publisher: Springer New York
Date: 2016
Publisher: Springer Science and Business Media LLC
Date: 26-01-2006
Abstract: Human sperm protein 17 (Sp17) is a highly conserved protein that was originally isolated from a rabbit epididymal sperm membrane and testis membrane pellet. It has recently been included in the cancer/testis (CT) antigen family, and shown to be expressed in multiple myeloma and ovarian cancer. We investigated its immunolocalisation in specimens of nervous system (NS) malignancies, in order to establish its usefulness as a target for tumour-vaccine strategies. The expression of Sp17 was assessed by means of a standardised immunohistochemical procedure [(mAb/antigen) MF1/Sp17] in formalin-fixed and paraffin embedded surgical specimens of NS malignancies, including 28 neuroectodermal primary tumours (6 astrocytomas, 16 glioblastoma multiforme, 5 oligodendrogliomas, and 1 ependymoma), 25 meningeal tumours, and five peripheral nerve sheath tumours (4 schwannomas, and 1 neurofibroma),. A number of neuroectodermal (21%) and meningeal tumours (4%) were found heterogeneously immunopositive for Sp17. None of the peripheral nerve sheath tumours was immunopositive for Sp17. The expression pattern was heterogeneous in all of the positive s les, and did not correlate with the degree of malignancy. The frequency of expression and non-uniform cell distribution of Sp17 suggest that it cannot be used as a unique immunotherapeutic target in NS cancer. However, our results do show the immunolocalisation of Sp17 in a proportion of NS tumour cells, but not in their non-pathological counterparts. The emerging complex function of Sp17 makes further studies necessary to clarify the link between it and immunopositive cells.
Publisher: Elsevier BV
Date: 05-2012
DOI: 10.1016/J.WNEU.2011.09.006
Abstract: The need for new and objective indexes for the neuroradiologic follow-up of brain tumors and for monitoring the effects of antiangiogenic strategies in vivo led us to perform a technical study on four patients who received computerized analysis of tumor-associated vasculature with ultra-high-field (7 T) magnetic resonance imaging (MRI). The image analysis involved the application of susceptibility weighted imaging (SWI) to evaluate vascular structures. Four patients affected by recurrent malignant brain tumors were enrolled in the present study. After the first 7-T SWI MRI procedure, the patients underwent antiangiogenic treatment with bevacizumab. The imaging was repeated every 2 weeks for a period of 4 weeks. The SWI patterns visualized in the three MRI temporal sequences were analyzed by means of a computer-aided fractal-based method to objectively quantify their geometric complexity. In two clinically deteriorating patients we found an increase of the geometric complexity of the space-filling properties of the SWI patterns over time despite the antiangiogenic treatment. In one patient, who showed improvement with the therapy, the fractal dimension of the intratumoral structure decreased, whereas in the fourth patient, no differences were found. The qualitative changes of the intratumoral SWI patterns during a period of 4 weeks were quantified with the fractal dimension. Because SWI patterns are also related to the presence of vascular structures, the quantification of their space-filling properties with fractal dimension seemed to be a valid tool for the in vivo neuroradiologic follow-up of brain tumors.
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 11-2019
Publisher: IEEE
Date: 13-04-2021
Publisher: MDPI AG
Date: 21-02-2023
DOI: 10.3390/IJMS24054283
Abstract: Proteomics offers vast potential for studying the molecular regulation of the human brain. Formalin fixation is a common method for preserving human tissue however, it presents challenges for proteomic analysis. In this study, we compared the efficiency of two different protein-extraction buffers on three post-mortem, formalin-fixed human brains. Equal amounts of extracted proteins were subjected to in-gel tryptic digestion and LC-MS/MS. Protein, peptide sequence, and peptide group identifications protein abundance and gene ontology pathways were analyzed. Protein extraction was superior using lysis buffer containing tris(hydroxymethyl)aminomethane hydrochloride, sodium dodecyl sulfate, sodium deoxycholate, and Triton X-100 (TrisHCl, SDS, SDC, Triton X-100), which was then used for inter-regional analysis. Pre-frontal, motor, temporal, and occipital cortex tissues were analyzed by label free quantification (LFQ) proteomics, Ingenuity Pathway Analysis and PANTHERdb. Inter-regional analysis revealed differential enrichment of proteins. We found similarly activated cellular signaling pathways in different brain regions, suggesting commonalities in the molecular regulation of neuroanatomically-linked brain functions. Overall, we developed an optimized, robust, and efficient method for protein extraction from formalin-fixed human brain tissue for in-depth LFQ proteomics. We also demonstrate herein that this method is suitable for rapid and routine analysis to uncover molecular signaling pathways in the human brain.
Publisher: Springer Science and Business Media LLC
Date: 26-02-2015
DOI: 10.1007/S12022-015-9361-Z
Abstract: Improved imaging techniques have contributed to increased diagnosis of pituitary tumors. These tumor types can be microadenomas or macroadenomas and can either be functional or non-functional. Atypical or aggressive pituitary adenomas are tumors that rapidly increase in size and may invade into the suprasellar or parasellar regions. They are characterized by a Ki-67 nuclear labeling index greater than 10 %. Management of these tumors is difficult, and many recur after surgery. Temozolomide, a second generation alkylating agent, has been showing promising results in the treatment of these tumors. The patient was a 39-year-old male diagnosed with an invasive silent somatotroph pituitary macroadenoma treated with temozolomide after surgery. We present the case along with the review of the literature of the therapeutic effects of temozolomide in somatotroph macroadenomas.
Publisher: Springer Science and Business Media LLC
Date: 15-01-2010
DOI: 10.1007/S10072-009-0197-5
Abstract: Mechanical stabilization of oncological vertebral fractures with cement augmentation is the first mechanism of pain relief, with or without restoration of vertebral body height. The aim of this study was to assess the safety and efficacy of vertebroplasty for painful vertebral body fractures in patients with multiple myeloma, in each phase of the disease. The authors reviewed a consecutive group of patients with multiple myeloma who underwent vertebroplasty at our Institute between November 2003 and December 2005. Twenty-eight levels were performed on 11 patients during 14 treatment sessions. All patients suffered from intractable back pain, and presented various lesion types (with and without fractures of posterior wall, and with and without epidural disease). The preoperative median visual analog scale (VAS) score was 7. The median duration of symptoms was 1.1 months. Eight patients were ambulating with orthopaedic devices (57%) in the pre-treatment period. Improvement or complete pain relief was observed in all patients (immediately in 8 cases, and after 2 days in 6 cases). The median VAS pain score decreased to 2. There was no symptomatic procedure-related complication. There were three cases (21%) of PMMA leakage: in the disc space in one case (7%), and in the anterior spinal canal in two cases (14%). Complete removal of orthopaedic devices was obtained in five patients (36%). No new deformation or collapse of the treated vertebrae was observed during the follow-up (range 1 day-25 months). In conclusion, vertebroplasty is a safe and efficient procedure in the treatment of painful vertebral body fractures in patients with multiple myeloma, without potential contraindications, such as fractures of the posterior wall or epidural disease. We also treated three and more levels in 28% of cases in a single session without complications. Due to the early pain relief and the low complication rate, it is possible to expand the indication to vertebroplasty for the prophylactic augmentation of those vertebral bodies at risk of fracture in which significant neoplastic substitution of the body is present.
Publisher: Elsevier BV
Date: 07-2019
Publisher: Springer New York
Date: 2016
Publisher: MyJove Corporation
Date: 11-05-2011
DOI: 10.3791/2718
Publisher: Journal of Neurosurgery Publishing Group (JNSPG)
Date: 10-2012
Abstract: The course of the trigeminal nerve straddles multiple fossae and is known to be very complex. Comprehensive anatomical knowledge and skull base techniques are required for surgical management of trigeminal schwannomas. The aims of this study were to become familiar with the endoscopic anatomy of the trigeminal nerve and to develop a minimally invasive surgical strategy for the treatment of trigeminal schwannomas. Ten fresh cadavers were studied using 5 endoscopic approaches with the aid of 4-mm 0° and 30° endoscopes to identify surgical landmarks associated with the trigeminal nerve. The endoscopic approaches included 3 transcranial keyhole approaches (the extradural supraorbital, extradural subtemporal, and retrosigmoid approaches), and 2 endonasal approaches (the transpterygoid and the transmaxillary transpterygoid approaches). The trajectories of the extradural supraorbital, transpterygoid, and extradural subtemporal approaches corresponded with the course of the first, second, and third isions of the trigeminal nerve, respectively. The 3 approaches demonstrated each ision in intra- and extracranial spaces, as well as the Meckel cave in the middle cranial fossa. The interdural space at the lateral wall of the cavernous sinus was exposed by the extradural supraorbital and subtemporal approaches. The extradural subtemporal approach with anterior petrosectomy and the retrosigmoid approach visualized the trigeminal sensory root and its neighboring neurovascular structures in the posterior cranial fossa. The transmaxillary transpterygoid approach revealed the course of the third ision in the infratemporal fossa. The 5 endoscopic approaches effectively followed the course of the trigeminal nerve with minimal invasiveness. These approaches could provide alternative options for the management of trigeminal schwannoma.
Publisher: Springer New York
Date: 2016
Publisher: Springer Science and Business Media LLC
Date: 06-04-2020
Publisher: Elsevier BV
Date: 09-2013
DOI: 10.1016/J.MVR.2013.04.009
Abstract: The idea that microvasculature might be a histopathological biomarker in the prognosis and treatment of tumors is garnering even more attention in the scientific community. The roles of neovascularity in tumor progression and metastasis, have become a hot-topic of investigation in cancer research. A number of methods of quantitatively analyzing pituitary adenoma microvasculature have been applied, and fractal analysis is emerging as a potential effective model for this aim. Additionally, new and more specific immunological techniques have been developed for the detection of microvessels. CD105 (Endoglin) has been proposed as a valuable antigen that marks only newly formed vessels, rather than the entire tumor microvascular system. The combination of different types of immunostaining techniques for the detection of microvessels in pituitary adenomas with fractal analysis as an objective and computer-aided technique to quantify and describe morphological aspects of microvessels has potential implications in future clinical and surgical applications. Tumor treatments, such as anti-angiogenic therapy, as well as intraoperative tools, stand to be enhanced by increasing advances in microvascular research. We here review the methods used for the quantitative analysis of microvessels of the pituitary in its physiopathological states, with the aim to show the pituitary adenoma as a model for the study of neoplastic angioarchitecture and the importance of the introduction of new techniques for the study of angiogenesis, with the relative scientific, medical and surgical implications.
Publisher: Springer New York
Date: 2016
Publisher: Springer Science and Business Media LLC
Date: 11-11-2012
DOI: 10.1007/S00701-011-1220-1
Abstract: In the past, sporadic demonstrations of the existence of a subarachnoid subdiaphragmatic cistern have been published. The aim of this study was to evaluate the anatomical characteristics of the subdiaphragmatic cistern of the pituitary gland. After a complete review of the literature published on the topic, we report anatomical observations of the subdiaphragmatic cistern and its relationship to the pituitary gland and to the chiasmatic cistern. Ten cadaveric heads were studied using different techniques and surgical methods (plastination, plastic casts of the subarachnoid spaces, microscopic and transsphenoidal endoscopic approaches). Moreover, 3-T magnetic resonance images of ten healthy volunteers were analyzed to investigate the presence and anatomical variability of the subdiaphragmatic cistern. By means of our qualitative radioanatomic study, we found that the roof of the subdiaphragmatic cistern is formed by the diaphragma sellae, the floor by the superior face of the pituitary gland, the lateral walls by the arachnoidea extending laterally through the medial walls of the cavernous sinus, and the medial walls by the infundibular stem. The subdiaphragmatic cistern communicates by means of the ostium of the diaphragm with the chiasmatic cistern. We confirmed the existence of the subdiaphragmatic cistern. The overused term "suprasellar cistern" refers more to a complex of cisterns, formed by the subdiaphragmatic cistern, below the diaphragma sella, and by the chiasmatic cistern, above it, in direct communication with the lamina terminalis and carotid cisterns.
Publisher: Springer Science and Business Media LLC
Date: 22-08-2019
DOI: 10.1038/S41598-019-48277-Z
Abstract: The ever decreasing area of forests has lead to environmental and economical challenges and has brought with it a renewed interest in developing methodologies that quantify the extent of deforestation and reforestation. In this study we analyzed the deforested areas of the Apuseni Mountains, which has been under economic pressure in recent years and resulted in widespread deforestation as a means of income. Deforested surface dynamics modeling was based on images contained in the Global Forest Database, provided by the Department of Geographical Sciences at Maryland University between 2000 and 2014. The results of the image particle analysis and modelling were based on Total Area (ha), Count of patches and Average Size whereas deforested area distribution was based on the Local Connected Fractal Dimension, Fractal Fragmentation Index and Tug-of-War Lacunarity as indicators of forest fragmentation or heterogeneity. The major findings of the study indicated a reduction of the tree cover area by 3.8%, an increase in fragmentation of 17.7% and an increase in heterogeneity by 29%, while fractal connectivity decreased only by 0.1%. The fractal and particle analysis showed a clustering of forest loss areas with an average increase from 1.1 to 3.0 ha per loss site per year. In conclusion, the fractal and particle analysis provide a relevant methodological framework to further our understanding of the spatial effects of economic pressure on forestry.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2014
Publisher: IEEE
Date: 06-2014
Publisher: Springer Science and Business Media LLC
Date: 13-01-2016
DOI: 10.1007/S11102-015-0703-0
Abstract: This publication reviews the function of arginine vasopressin and focuses on the morphologic and functional correlation between the hormone and its effect on stress, the hypophysial-adrenocortical axis, neuroimmune responses, renal function and corticotroph pituitary tumors. A literature review was performed using various search engines for information regarding the morphology and the multifunctional role of arginine vasopressin. Although a large number of studies were published discussing these interactions, there are several important areas that are still obscure. The questions of how does arginine vasopressin affect the morphology and function of these various areas, and how does the secretion of ACTH and adrenocortical hormones influence the morphology of arginine vasopressin-producing cells and their hormone secretion requires further investigation.
Publisher: The Endocrine Society
Date: 11-2022
DOI: 10.1210/JENDSO/BVAC150.1068
Abstract: Thyrotropin secreting pituitary adenoma (TSHoma) of the pituitary specific transcription factor-1 (PIT-1) lineage, is the rarest subtype of pituitary neuroendocrine tumours (pitNETs). TSHomas must be discriminated from primary hyperthyroidism and can cause morbidity through thyrotoxicosis or local mass effect. Serum alpha-subunit level may be used as a marker of tumour activity, as 50-85% of TSHoma patients have high serum alpha-subunit levels. First line treatment is surgical resection of the tumour. Medical therapy with somatostatin analogues or radiotherapy may be used for tumour control. Epidermal growth factor receptor (EGFR) expression has been demonstrated in pitNETs including corticotrophs, gonadotrophs, lactotrophs and somatotrophs. EGFR inhibiting agent, Lapatinib, has been investigated for treatment of prolactinomas and EGFR expression is implicated in tumorigenesis of corticotrophs. EGFR targeting tyrosine kinase inhibitors (TKIs) can be used first line to treat metastatic adenocarcinoma of the lung harbouring activating EGFR mutations. A non-smoking 53-year-old male of Middle Eastern heritage was seen in clinic with secondary hyperthyroidism on a background of metastatic adenocarcinoma of the lung and hypertension. The patient had no symptoms of hyperthyroidism and had no personal or family history of thyroid dysfunction. No new headaches or visual disturbance were reported. Physical exam showed brisk reflexes, no specific signs of hyperthyroidism or thyromegaly were seen. Thyroid function tests demonstrated a persistently elevated TSH 5.1mIU/L (0.4-4. 0), T4 21.8pmol/L (9-19) and T3 6.4pmol/L (2.6-6. 0) with negative anti- thyroid receptor, thyroperoxidase and thyroglobulin antibodies. Ultrasound of the thyroid was unremarkable. MRI revealed a well-circumscribed left anterior pituitary lesion of 5.4×6.8mm in size. Surgery was deferred as 3 months prior, he was diagnosed with stage 4 intrapulmonary adenocarcinoma of the lung with an exon-19 deletion mutation in the EGFR gene. He received stereotactic radiotherapy and EGFR targeted therapy using 100mg of Erlotinib daily, which increased to 200mg 6 months later. After 1 year of therapy, his adenocarcinoma progressed and he was transitioned to the 3 rd generation EGFR-TKI Osimertinib. Instead of undergoing the risk of pituitary surgery, a trial of EGFR therapy for its pleiotropic pituitary adenoma effects was decided. During the EGFR-TKI treatment period, alpha subunit levels have remained stable and serial MRI imaging at 1 year showed no interval pituitary adenoma growth. This is a rare case of TSHoma identified during treatment of lung cancer with EGFR-TKIs. EGFR signalling is implicated in prolactinomas and corticotrophs though there is a paucity of data regarding TSHomas. To date, our patient has achieved radiological and biochemical stability in his TSHoma, with hyperthyroidism control on EGFR-TKI therapy, suggestive of a therapeutic benefit from EGFR signal blockade. Further studies are needed in larger cohorts to quantify EGFR expression in TSHomas and evaluate its possible role in pathogenesis. Presentation: No date and time listed
Publisher: Springer Science and Business Media LLC
Date: 15-12-2015
Abstract: Human kallikrein-like peptidase 10 (KLK10), a serine protease, plays an important role in the regulation of cell proliferation and tumor growth. In this work, we investigated KLK10 immunoexpression in various types of surgically removed human pituitary tumors. Specimens were fixed in formalin and embedded in paraffin. Immunostaining was performed by the streptavidin-biotin-peroxidase complex protocol using the LSAB+ Kit and a KLK10-specific rabbit polyclonal antibody. Results showed that both treated and untreated prolactin-producing pituitary adenomas and carcinomas as well as TSH-producing pituitary adenomas and carcinomas were conclusively immunopositive for KLK10. Immunostaining was mainly localized in the cytoplasm and was clearly visible in many adenoma cells. In various other tumor types (oncocytoma, gonadotroph, somatotroph adenomas, and carcinomas), cytoplasmic immunopositivity was mild to moderate and seen only in a few unevenly distributed adenoma cells. Immunopositivity in the nuclei of various tumor types, as well as dual cytoplasmic and nuclear localization of KLK10 in some of the tumor types, was an intriguing finding. Immunoexpression in GH-producing adenomas exposed to octreotide, a long-acting somatostatin analog, was significantly increased when compared to unexposed GH-producing tumors. More studies are needed to ascertain the role of KLK10 in pituitary tumor development, prognosis, and progression. The question of whether genetic abnormalities and the microenvironment can affect KLK10 immunoexpression should also be investigated.
Publisher: The Endocrine Society
Date: 11-2022
DOI: 10.1210/JENDSO/BVAC150.1060
Abstract: Silent corticotroph adenomas (SCA) are characterised by an absence of cortisol excess yet show positive immunostaining for T-Box transcription factor (TPIT) and frequently adrenocorticotropic hormone (ACTH). Patients with a SCA commonly present with symptoms of mass effect such as headache or visual compromise or are identified incidentally on imaging. SCAs are high risk according to the WHO 2017 classification scheme. To assess our cohort of SCAs for differences in demographics, presenting symptoms and imaging results compared to other non-functioning pituitary adenomas (NFPA). Surgically treated patients with NFPAs seen by endocrinology at an Australian Tertiary Centre between the years 2011-2021 were included in the analysis. SCA was diagnosed based on the absence of clinical and biochemical features of cortisol excess in combination with immunohistochemical staining including positive staining for ACTH. Other NFPA subtypes were defined by immunohistochemical staining and the absence of hormone overproduction. We compared demographic information, symptoms at presentation and tumour size as assessed by magnetic resonance imaging (MRI) between the SCA and all other NFPA groups. Where available, pre- and postoperative ACTH and cortisol levels were compared in the SCA and non-SCA groups. 31 patients were identified, 5 with SCA and 26 with other NFPA, all were macroadenomas. All 5 cases of SCA showed ACTH positivity, 2 of 5 cases were stained for TPIT, both were positive. Mean age at surgery for the SCA group was 50.8±10.9 years. Mean non-SCA age was 54.3±15.4 years. 3 of the 5 patients with SCA were women. The most frequent symptoms at presentation were headache (SCA: 40% non-SCA 36%) and visual disturbances (SCA: 60% non-SCA 68%). The mean maximal tumour diameter in the SCA group was 31.36±13.61 mm versus 24.65±6.80 mm in the non-SCA group on MRI. Cavernous sinus invasion was present in 60% of the SCA and 38.5% of the non-SCA group. In the SCA group pre-operative ACTH levels were 5.1±2.6 pmol/L (normal & .1 pmol/L) and dropped to 2.5±1.8 pmol/L postoperatively. Cortisol levels were 344±205 nmol/L (normal 138-650 nmol/L) and dropped to 269±228 nmol/L. In the non-SCA group ACTH levels were 4.5±2.3 pmol/L preoperatively and 4.6±3.8 pmol/L postoperatively. Cortisol levels were and 538±168 nmol/L preoperatively and 403±179 nmol/L postoperatively. In this retrospective comparison, compared to other NFPAs the SCA group showed younger age, more frequent headaches, less visual compromise, larger tumour size and increased cavernous sinus invasion. These findings are consistent with the known aggressiveness of SCAs. The reduction in ACTH levels postoperatively support the concept that SCAs produce inactive forms of ACTH. Although this is a small case series, there may be merit in monitoring for relative increases in ACTH levels in patients with a history of SCA. Presentation: No date and time listed
Publisher: Springer Science and Business Media LLC
Date: 05-2008
Publisher: Elsevier BV
Date: 07-2015
DOI: 10.1016/J.WNEU.2015.02.030
Abstract: Osteomalacia-inducing tumors (OIT) are mesenchymal tumors that characteristically secrete fibroblast growth factor 23, resulting in a paraneoplastic syndrome of hypophosphatemic osteomalacia. These tumors are known to occur in soft tissues and bones in various sites. It is very unusual for OITs to occur intracranially, with only 10 reported intracranial cases since their discovery in 1959. The most common intracrainal OITs are phosphaturic mesenchymal tumors and hemangiopericytomas. We report a case of hypophosphatemic osteomalacia caused by a tumor in the right anterior cranial fossa. We also hypothesize, based on our review of the literature, that this entity is underdiagnosed. A 49-year-old woman had a history of a nonhealing ankle fracture that required repeated surgery over 3 years. She subsequently was found to have severe hypophosphatemia and evidence of osteomalacia together with multiple occult fractures. A diagnosis of tumor-induced osteomalacia was suspected. An elevated serum fibroblast growth factor 23 level confirmed the diagnosis. An octreotide scan that was performed to locate the responsible tumor revealed an area of avid uptake in the right frontal lobe. Magnetic resonance imaging showed a large right anterior fossa extra-axial mass. The patient was referred for surgical intervention and was cured clinically after surgical removal of the tumor. Pathologic examination revealed a phosphaturic mesenchymal OIT. Her phosphate levels returned to normal 3 weeks after surgery. The diagnosis of OIT should be considered in a case of severe hypophosphatemia and metabolic bone disease that is not explained by any other metabolic or hereditary disease. These tumors can occur intracranially and may be confused with a meningioma or a hemangiopericytoma. Taking OIT into consideration in such cases could lead to a shorter time to diagnosis and management, which in our case took 4 years.
Publisher: Springer Nature Switzerland
Date: 2022
Publisher: Springer Science and Business Media LLC
Date: 29-05-2019
DOI: 10.1007/S00701-019-03954-W
Abstract: Microvascular decompression (MVD) is an effective treatment for drug-resistant trigeminal neuralgia and hemifacial spasm. However, failure of symptomatic improvement can arise from difficulties in identifying and/or decompressing the offending vessel. Microscopic and endoscopic techniques have been used to improve visualisation and safety of the procedure but there are limitations to each technique. A 3D exoscopic endoscope-assisted MVD technique is described, including advice on potential pitfalls. Compared with the standard microscope-assisted techniques, the 3D exoscopic endoscope-assisted MVD offers an improved visualisation without compromising the field of view within and outside the surgical field.
Publisher: Elsevier BV
Date: 2011
Publisher: SAGE Publications
Date: 06-02-2013
Abstract: The monitoring of intracranial pressure (ICP) is an important tool in medicine for its ability to portray the brain’s compliance status. The bedside monitor displays the ICP waveform and intermittent mean values to guide physicians in the management of patients, particularly those having sustained a traumatic brain injury. Researchers in the fields of engineering and physics have investigated various mathematical analysis techniques applicable to the waveform in order to extract additional diagnostic and prognostic information, although they largely remain limited to research applications. The purpose of this review is to present the current techniques used to monitor and interpret ICP and explore the potential of using advanced mathematical techniques to provide information about system perturbations from states of homeostasis. We discuss the limits of each proposed technique and we propose that nonlinear analysis could be a reliable approach to describe ICP signals over time, with the fractal dimension as a potential predictive clinically meaningful biomarker. Our goal is to stimulate translational research that can move modern analysis of ICP using these techniques into widespread practical use, and to investigate to the clinical utility of a tool capable of simplifying multiple variables obtained from various sensors.
Publisher: Springer Science and Business Media LLC
Date: 06-12-2018
Publisher: Journal of Neurosurgery Publishing Group (JNSPG)
Date: 09-2022
DOI: 10.3171/2022.6.FOCUS22243
Abstract: Giovanni Andrea Dalla Croce was a Venetian physician who lived in the 16th century and was famous for his treatment of wounds, which was surprisingly modern. He was the military surgeon of the Venetian Republic’s naval fleet. In 1537, he published the Chirurgiae universalis opus absolutum ( The absolute work on universal surgery ) in Latin, then expanded and translated into vernacular Italian and published in 1574 with the title Cirugia universale e perfetta di tutte le parti pertinenti all’ottimo chirurgo ( Universal and perfect surgery of all the parts necessary for the optimal surgeon ). This monumental work was a comprehensive handbook of surgery, medicine, and the treatment of many kinds of wounds with techniques to be used on the battlefield. It is also notable for the inclusion of illustrations of various weapons and projectiles, for the most comprehensive description and illustrations of surgical instruments at that time, and for the first illustrations of a surgeon performing trephination of the skull in an operating room. Dalla Croce also considered the writings of his surgical forebears in formulating his own ideas. Dalla Croce was a leader of traumatology, a universal surgeon who exemplified the erudite Renaissance man, and left a tremendous legacy to military surgery of the 16th century and beyond.
Publisher: IEEE
Date: 11-2021
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.WNEU.2019.10.026
Abstract: Paulus of Aegina (625-690 ad) was the last of the prolific Byzantine physicians. His works consolidated and extended the knowledge of his predecessors, with pioneering efforts to improve the surgical management of spinal injuries. In this article, we review the literature to present an overview of the remarkable evolution of spine surgery throughout classical antiquity. In particular, we discuss the contributions of Paulus to this corpus and explore his classic 7-book anthology, Epitomoe Medicae Libri Septem (Medical Compendium in Seven Books). In reviewing Paulus' legacy, we show the significant milestones in the early development of anatomic and functional knowledge of the spine.
Publisher: Springer Science and Business Media LLC
Date: 30-10-2013
DOI: 10.1007/S00701-013-1919-2
Abstract: Thin aneurysm wall thickness (AWT) is thought to portend an elevated risk of intracranial aneurysm rupture. Magnetic resonance imaging (MRI) is biased by AWT overestimations. Previously, this suspected bias has been qualitatively described but never quantified. We aimed to quantify the overestimation of AWT by MRI when compared to the gold standard of AWT as measured by light microscopy of fresh aneurysm specimens (without any embedding procedure). This analysis should help to define the clinical potential of MRI estimates of AWT. 3-Tesla (3T) MRI (contrast-enhanced T1 Flash sequences resolution: 0.4 x 0.4 x 1.5 mm(3)) was performed in 13 experimental aneurysms. After MR acquisition, the aneurysms were retrieved, longitudinally sectioned and calibrated micrographs were obtained immediately. AWT at the dome, AWT at the neck and parent vessel wall thickness (PVT) were measured on precisely correlated MR-images and histologic micrographs by blinded independent investigators. Parameters were statistically compared (Wilcoxon test, Spearman's correlation). AWT was assessed and reliably measured using MRI. Interobserver variability was not significant for either method. MR overestimation was only significant below the image resolution threshold: AWT at the dome (0.24 ± 0.06 mm vs. MR 0.30 ± 0.08 mm p = 0.0078 R = 0.6125), AWT at the neck (0.25 ± 0.07 mm vs. MR 0.29 ± 0.07 mm p = 0.0469 R = 0.7451), PVT (0.46 ± 0.06 mm vs. MR 0.48 ± 0.06 mm p = 0.5 R = 0.8568). In this experimental setting, MR overestimations were minimal (mean 0.02 mm) above the image resolution threshold. When AWT is classified in ranges defined by the MR resolution threshold, clinical usage may be beneficial. Further quantitative and comparative experimental and human studies are warranted to confirm these findings.
Publisher: Oxford University Press (OUP)
Date: 31-12-2016
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2016
Publisher: Elsevier BV
Date: 05-2022
DOI: 10.1016/J.JOCN.2022.03.023
Abstract: Brain arteriovenous malformation (bAVM) resection imposes several post-operative clinical challenges including intracranial haemorrhage (ICH). Daily non-invasive monitoring of haemodynamic measurements may be useful in predicting post-operative ICH. This prospective study used transcranial colour duplex (TCCD) and central aortic pressure (CAP) measurements to evaluate 15 bAVM patients pre-operatively and daily ≤ 14 days post-operatively. TCCD measurements of middle cerebral artery and veins included peak systolic (PSV), end diastolic (EDV), and pulsatility indices (PI). Parameters were compared with 7 craniotomy patients (non-bAVM craniotomy/surgical group). Normal reference values included 20 healthy volunteers. Significant middle cerebral vein MCV changes in bAVM patients occurred Maximal PSV was significantly higher (median 47 cm/s) compared to non-bAVM craniotomy/surgical controls (median 17 cm/s, p = 0.0123) maximal PI was significantly higher (median 0.99, p = 0.005) compared to the non-bAVM craniotomy/surgical controls (median 0.49). In 8 of 15 patients, increased MCV velocity and pulsatility "stabilised" within 14 days post-operatively. Mean number of days for the 8 patients to reach stable state was 5.9 days, (range 0-9 days). To our knowledge, this is the first imaging study demonstrating significant venous changes post bAVM resection. Significant increased venous flow occurs in pial veins bilaterally. Increased pressure of venous flow is evidenced by a significant increase in diameter and pulsatility. Subsequently, haemorrhagic complications may be due distal constriction of the pial veins causing venous hypertension. The cause of the dilated vascular bed is unknown.
Publisher: IEEE
Date: 05-2017
DOI: 10.1109/CSCS.2017.53
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2012
Publisher: MDPI AG
Date: 28-07-2023
Abstract: Radiomics is a rapidly evolving field that involves extracting and analysing quantitative features from medical images, such as computed tomography or magnetic resonance images. Radiomics has shown promise in brain tumor diagnosis and patient-prognosis prediction by providing more detailed and objective information about tumors’ features than can be obtained from the visual inspection of the images alone. Radiomics data can be analyzed to determine their correlation with a tumor’s genetic status and grade, as well as in the assessment of its recurrence vs. therapeutic response, among other features. In consideration of the multi-parametric and high-dimensional space of features extracted by radiomics, machine learning can further improve tumor diagnosis, treatment response, and patients’ prognoses. There is a growing recognition that tumors and their microenvironments (habitats) mutually influence each other—tumor cells can alter the microenvironment to increase their growth and survival. At the same time, habitats can also influence the behavior of tumor cells. In this systematic review, we investigate the current limitations and future developments in radiomics and machine learning in analysing brain tumors and their habitats.
Publisher: Journal of Neurosurgery Publishing Group (JNSPG)
Date: 12-2015
Abstract: Susceptibility weighted imaging (SWI) is a relatively new imaging technique. Its high sensitivity to hemorrhagic components and ability to depict microvasculature by means of susceptibility effects within the veins allow for the accurate detection, grading, and monitoring of brain tumors. This imaging modality can also detect changes in blood flow to monitor stroke recovery and reveal specific subtypes of vascular malformations. In addition, small punctate lesions can be demonstrated with SWI, suggesting diffuse axonal injury, and the location of these lesions can help predict neurological outcome in patients. This imaging technique is also beneficial for applications in functional neurosurgery given its ability to clearly depict and differentiate deep midbrain nuclei and close submillimeter veins, both of which are necessary for presurgical planning of deep brain stimulation. By exploiting the magnetic susceptibilities of substances within the body, such as deoxyhemoglobin, calcium, and iron, SWI can clearly visualize the vasculature and hemorrhagic components even without the use of contrast agents. The high sensitivity of SWI relative to other imaging techniques in showing tumor vasculature and microhemorrhages suggests that it is an effective imaging modality that provides additional information not shown using conventional MRI. Despite SWI’s clinical advantages, its implementation in MRI protocols is still far from consistent in clinical usage. To develop a deeper appreciation for SWI, the authors here review the clinical applications in 4 major fields of neurosurgery: neurooncology, vascular neurosurgery, neurotraumatology, and functional neurosurgery. Finally, they address the limitations of and future perspectives on SWI in neurosurgery.
Publisher: Elsevier BV
Date: 02-2013
DOI: 10.1016/J.WNEU.2011.02.045
Abstract: Adequate training based on cadaveric dissection is essential to acquire a practical knowledge of surgical anatomy and microsurgical/endoscopic dissection techniques. Endoscopic procedures for the treatment of pathologies of the skull base are becoming increasingly common. The endoscopic training curve for tool handling and a detailed knowledge of the topographic anatomy of the skull base require intensive training on cadavers before approaching living patients, which is why cadaver laboratory experience should be mandatory for every resident and surgeon preparing to use microsurgical and endoscopic techniques. We describe the basic principles of the philosophy of anatomic dissection and the equipment necessary to set up an endoscopic cadaver laboratory.
Publisher: Informa UK Limited
Date: 03-05-2016
DOI: 10.1080/17446651.2016.1179110
Abstract: Pituitary carcinoma is a rare tumor originating from adenohypophyseal cells. Currently, erse pathogenetic mechanisms, i.e. de novo versus malignant transformation from pituitary adenoma, remain obscure and require further investigation. During the last two decades, scientific research added new horizons not only in regards to general tumor concepts but also in next generation biomarker armamentarium that sheds light on alternate pathways in carcinogenesis. Areas covered: In this review, the impact of apoptotic and proliferative markers, angiogenesis, telomerase activity, H-ras, HIF-1, HER-2/neu, Rb gene, and microRNAs in pathogenetic mechanisms of pituitary carcinomas were revised. Expert commentary: It is becoming increasingly important for the need of standardization of new biomarkers but also for better comprehension of the erse pathways in tumorigenesis. This can only be accomplished by tapping into the continuously expanding spectrum of new biomarkers.
Publisher: Elsevier BV
Date: 08-2006
DOI: 10.1016/J.SURNEU.2005.11.058
Abstract: Paget's disease is an osteometabolic disorder affecting in particular long bones. The spine is the second most commonly involved site in Paget's disease. This pathology can cause low back pain, spinal stenosis, myeloradiculopathy, and vertebral collapse. Medical therapy is the first choice for the treatment of Paget's disease of the spine in case of failure, surgery remains a valid option. In the present article, we report a case of a patient with leg disability due to myelopathy caused by spinal Paget's disease treated with spinal decompression and vertebroplasty. To our knowledge, this is the first case report in which these procedures have been performed together in the same operation to treat spinal pathologies due to Paget's disease.
Publisher: Springer Science and Business Media LLC
Date: 13-12-2012
Publisher: MDPI AG
Date: 30-09-2022
DOI: 10.3390/S22197438
Abstract: Recent studies matching eye gaze patterns with those of others contain research that is heavily reliant on string editing methods borrowed from early work in bioinformatics. Previous studies have shown string editing methods to be susceptible to false negative results when matching mutated genes or unordered regions of interest in scanpaths. Even as new methods have emerged for matching amino acids using novel combinatorial techniques, scanpath matching is still limited by a traditional collinear approach. This approach reduces the ability to discriminate between free viewing scanpaths of two people looking at the same stimulus due to the heavy weight placed on linearity. To overcome this limitation, we here introduce a new method called SoftMatch to compare pairs of scanpaths. SoftMatch erges from traditional scanpath matching in two different ways: firstly, by preserving locality using fractal curves to reduce dimensionality from 2D Cartesian (x,y) coordinates into 1D (h) Hilbert distances, and secondly by taking a combinatorial approach to fixation matching using discrete Fréchet distance measurements between segments of scanpath fixation sequences. These matching “sequences of fixations over time” are a loose acronym for SoftMatch. Results indicate high degrees of statistical and substantive significance when scoring matches between scanpaths made during free-form viewing of unfamiliar stimuli. Applications of this method can be used to better understand bottom up perceptual processes extending to scanpath outlier detection, expertise analysis, pathological screening, and salience prediction.
Publisher: JMIR Publications Inc.
Date: 17-11-2020
DOI: 10.2196/19805
Abstract: The radiological differential diagnosis between tumor recurrence and radiation-induced necrosis (ie, pseudoprogression) is of paramount importance in the management of glioma patients. This research aims to develop a deep learning methodology for automated differentiation of tumor recurrence from radiation necrosis based on routine magnetic resonance imaging (MRI) scans. In this retrospective study, 146 patients who underwent radiation therapy after glioma resection and presented with suspected recurrent lesions at the follow-up MRI examination were selected for analysis. Routine MRI scans were acquired from each patient, including T1, T2, and gadolinium-contrast-enhanced T1 sequences. Of those cases, 96 (65.8%) were confirmed as glioma recurrence on postsurgical pathological examination, while 50 (34.2%) were diagnosed as necrosis. A light-weighted deep neural network (DNN) (ie, efficient radionecrosis neural network [ERN-Net]) was proposed to learn radiological features of gliomas and necrosis from MRI scans. Sensitivity, specificity, accuracy, and area under the curve (AUC) were used to evaluate performance of the model in both image-wise and subject-wise classifications. Preoperative diagnostic performance of the model was also compared to that of the state-of-the-art DNN models and five experienced neurosurgeons. DNN models based on multimodal MRI outperformed single-modal models. ERN-Net achieved the highest AUC in both image-wise (0.915) and subject-wise (0.958) classification tasks. The evaluated DNN models achieved an average sensitivity of 0.947 (SD 0.033), specificity of 0.817 (SD 0.075), and accuracy of 0.903 (SD 0.026), which were significantly better than the tested neurosurgeons (P=.02 in sensitivity and P .001 in specificity and accuracy). Deep learning offers a useful computational tool for the differential diagnosis between recurrent gliomas and necrosis. The proposed ERN-Net model, a simple and effective DNN model, achieved excellent performance on routine MRI scans and showed a high clinical applicability.
Publisher: Elsevier BV
Date: 04-2023
Publisher: Elsevier BV
Date: 08-2021
Publisher: Springer New York
Date: 2016
Publisher: Springer Science and Business Media LLC
Date: 27-02-2010
DOI: 10.1007/S10143-010-0249-6
Abstract: Magnetic resonance elastography (MRE) has been developed over the last few years as a non-invasive means of evaluating the elasticity of biological tissues. The presence of the skull has always prevented semeiotic palpation of the brain, but MRE now offers the possibility of "palpating by imaging" in order to detect brain consistency under physiological and pathological conditions. The aim of this article is to review the current state-of-the-art of MRE imaging and discuss its possible future diagnostic applications in neuroscience.
Publisher: Springer New York
Date: 2016
Publisher: Springer Science and Business Media LLC
Date: 07-04-2023
DOI: 10.1007/S10980-023-01640-Y
Abstract: Forest loss and fragmentation pose extreme threats to bio ersity. Their efficient characterization from remotely sensed data therefore has strong practical implications. Data are often separately analyzed for spatial fragmentation and disorder, but no existing metric simultaneously quantifies both the shape and arrangement of fragments. We present a fractal fragmentation and disorder index (FFDI), which advances a previously developed fractal index by merging it with the Rényi information dimension. The FFDI is designed to work across spatial scales, and to efficiently report both the fragmentation of images and their spatial disorder. We validate the FFDI with 12,600 synthetic hierarchically structured random map (HRM) multiscale images, as well as several other categories of fractal and non-fractal test images (4880 images). We then apply the FFDI to satellite imagery of forest cover for 10 distinct regions of the Romanian Carpathian Mountains from 2000–2021. The FFDI outperformed its two in idual components (fractal fragmentation index and Rényi information dimension) in resolving spatial patterns of disorder and fragmentation when tested on HRM classes and other image types. The FFDI thus offers a clear advantage when compared to the in idual use of fractal fragmentation index and the Information Dimension, and provided good classification performance in an application to real data. This work improves on previous characterizations of landscape patterns. With the FFDI, scientists will be able to better monitor and understand forest fragmentation from satellite imagery. The FFDI may also find wider applicability in biology wherever image analysis is used.
Publisher: Wiley
Date: 11-09-2007
Publisher: Springer New York
Date: 2016
Publisher: Springer International Publishing
Date: 2021
Publisher: Georg Thieme Verlag KG
Date: 10-2011
Abstract: Persistent trigeminal artery (PTA) is one of the carotid-basilar anastomoses and occasionally complicates vascular or neoplastic pathology. The aim of this study was to become more familiar with the anatomy associated with PTA using an endoscopic view. PTA was incidentally encountered in a fresh cadaver. Purely endoscopic approaches via supraorbital (extradural and intradural routes), endonasal, and retrosigmoid routes were performed with 4-mm, 0- and 30-degree rigid endoscopes. The PTA belonged to Salas's lateral type and Saltzman's type 1. The supraorbital extradural approach allowed good visualization of the origin and the cavernous portion of the PTA through the infratrochlear triangle. Using the endonasal route, the cisternal portion of the PTA and its confluence to the basilar artery were demonstrated after opening the clival dura however, the origin of the PTA and the cavernous portion of the PTA were not sufficiently exposed even using a direct approach to the cavernous sinus. The retrosigmoid approach revealed the anatomical relationship among the PTA, trigeminal nerve, and abducent nerve in the petroclival region. These 3 endoscopic approaches provided a superb image of the PTA and contribute to the anatomical comprehension of PTA. Additionally, these approaches make us more familiar with an endoscopic view of PTA.
Publisher: SAGE Publications
Date: 12-2014
Abstract: The AOCMF Classification Group developed a hierarchical three-level craniomaxillofacial (CMF) classification system with increasing level of complexity and details. The basic level 1 system differentiates fracture location in the mandible (code 91), midface (code 92), skull base (code 93), and cranial vault (code 94) the levels 2 and 3 focus on defining fracture location and morphology within more detailed regions and subregions. Correct imaging acquisition, systematic analysis, and interpretation according to the anatomic and surgical relevant structures in the CMF regions are essential for an accurate, reproducible, and comprehensive diagnosis of CMF fractures using that system. Basic principles for radiographic diagnosis are based on conventional plain films, multidetector computed tomography, and magnetic resonance imaging. In this tutorial, the radiological issues according to each level of the classification are described.
Publisher: Bioscientifica
Date: 06-05-2015
DOI: 10.1530/ERC-15-0042
Abstract: Autophagy is an important intracellular process involving the degradation of cytoplasmic components. It is involved in both physiological and pathological conditions, including cancer. The role of autophagy in cancer is described as a ‘double-edged sword,’ a term that reflects its known participation in tumor suppression, tumor survival and tumor cell proliferation. Available research regarding autophagy in endocrine cancer supports this concept. Autophagy shows promise as a novel therapeutic target in different types of endocrine cancer, inhibiting or increasing treatment efficacy in a context- and cell-type-dependent manner. At present, however, there is very little research concerning autophagy in endocrine tumors. No research was reported connecting autophagy to some of the tumors of the endocrine glands such as the pancreas and ovary. This review aims to elucidate the roles of autophagy in different types of endocrine cancer and highlight the need for increased research in the field.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 31-03-2022
Publisher: SAGE Publications
Date: 12-2014
Abstract: The AOCMF Classification Group developed a hierarchical three-level craniomaxillofacial classification system with increasing level of complexity and details. The highest level 1 system distinguish four major anatomical units, including the mandible (code 91), midface (code 92), skull base (code 93), and cranial vault (code 94). This tutorial presents the level 2 and more detailed level 3 systems for the skull base and cranial vault units. The level 2 system describes fracture location outlining the topographic boundaries of the anatomic regions, considering in particular the endocranial and exocranial skull base surfaces. The endocranial skull base is ided into nine regions a central skull base adjoining a left and right side are ided into the anterior, middle, and posterior skull base. The exocranial skull base surface and cranial vault are ided in regions defined by the names of the bones involved: frontal, parietal, temporal, sphenoid, and occipital bones. The level 3 system allows assessing fracture morphology described by the presence of fracture fragmentation, displacement, and bone loss. A documentation of associated intracranial diagnostic features is proposed. This tutorial is organized in a sequence of sections dealing with the description of the classification system with illustrations of the topographical skull base and cranial vault regions along with rules for fracture location and coding, a series of case ex les with clinical imaging and a general discussion on the design of this classification.
Publisher: Springer Science and Business Media LLC
Date: 24-08-2017
DOI: 10.1007/S10143-016-0776-X
Abstract: Following extended endoscopic transsphenoidal approach (EETSA), cerebrospinal fluid (CSF) leak rate has been reported in the range of 5-50 %. Novel closure techniques, such as the nasoseptal flap and other multilayered repairs improved the outcomes significantly but took most of our focus. Little attention, however, was given to other aspects of the equation such as nasal support-to support the heavy weight of such repairs-and lumbar drains. These are important because they diminish the forces acting on both sides of the repair, hence covering all the angles. We reviewed data of 98 consecutive patients who underwent an EETSA between 1999 and 2014. We analyzed the rates of CSF leak throughout the years and with every modification added to our closure technique. Common pathologies encountered were invasive adenomas, meningiomas, chordomas, and craniopharyngiomas. CSF leak occurred overall in five patients (5.1 %). The nasoseptal flap decreased the rate of CSF leak but not significantly (P = 0.112), while placing a nasal trumpet to support our repair resulted in significant decrease in CSF leak rate (P = 0.0013). In the last 2 years of our series, when all modifications took place and all angles were covered, there was one leak in 35 cases (2.8 %). A protocol that covers all the angles by a good multilayered repair (regardless of its type and materials) while diminishing the forces acting on both sides of the repair leads to a minimal rate of CSF leak. No principle alone is effective in idually.
Publisher: Wiley
Date: 17-12-2015
DOI: 10.1111/JON.12200
Abstract: Computational models have been investigated for the analysis of the physiopathology and morphology of arteriovenous malformation (AVM) in recent years. Special emphasis has been given to image fusion in multimodal imaging and 3-dimensional rendering of the AVM, with the aim to improve the visualization of the lesion (for diagnostic purposes) and the selection of the nidus (for therapeutic aims, like the selection of the region of interest for the gamma knife radiosurgery plan). Searching for new diagnostic and prognostic neuroimaging biomarkers, fractal-based computational models have been proposed for describing and quantifying the angioarchitecture of the nidus. Computational modeling in the AVM field offers promising tools of analysis and requires a strict collaboration among neurosurgeons, neuroradiologists, clinicians, computer scientists, and engineers. We present here some updated state-of-the-art exemplary cases in the field, focusing on recent neuroimaging computational modeling with clinical relevance, which might offer useful clinical tools for the management of AVMs in the future.
Publisher: Springer Science and Business Media LLC
Date: 27-05-2023
DOI: 10.1007/S12035-023-03355-2
Abstract: Amyotrophic lateral sclerosis (ALS)- and frontotemporal dementia (FTD)-linked mutations in CCNF have been shown to cause dysregulation to protein homeostasis. CCNF encodes for cyclin F, which is part of the cyclin F-E3 ligase complex SCF cyclinF known to ubiquitylate substrates for proteasomal degradation. In this study, we identified a function of cyclin F to regulate substrate solubility and show how cyclin F mechanistically underlies ALS and FTD disease pathogenesis. We demonstrated that ALS and FTD-associated protein sequestosome-1 62 (p62) was a canonical substrate of cyclin F which was ubiquitylated by the SCF cyclinF complex. We found that SCF cyclin F ubiquitylated p62 at lysine(K)281, and that K281 regulated the propensity of p62 to aggregate. Further, cyclin F expression promoted the aggregation of p62 into the insoluble fraction, which corresponded to an increased number of p62 foci. Notably, ALS and FTD-linked mutant cyclin F p.S621G aberrantly ubiquitylated p62, dysregulated p62 solubility in neuronal-like cells, patient-derived fibroblasts and induced pluripotent stem cells and dysregulated p62 foci formation. Consistently, motor neurons from patient spinal cord tissue exhibited increased p62 ubiquitylation. We suggest that the p.S621G mutation impairs the functions of cyclin F to promote p62 foci formation and shift p62 into the insoluble fraction, which may be associated to aberrant mutant cyclin F-mediated ubiquitylation of p62. Given that p62 dysregulation is common across the ALS and FTD spectrum, our study provides insights into p62 regulation and demonstrates that ALS and FTD-linked cyclin F mutant p.S621G can drive p62 pathogenesis associated with ALS and FTD.
Publisher: Elsevier BV
Date: 06-2005
DOI: 10.1016/J.CLINEURO.2004.07.017
Abstract: Calvarium is a frequent target site of involvement for common neoplasms. Some cases of calvarial metastases have been reported in literature as secondary lesions from renal cell carcinoma (RCC), but only five cases have been described concerning calvarial mass as the first clinical presentation of this kind of tumor. In this report, we discuss the clinical aspects of two further cases we observed, in which the renal cell carcinoma was found thanks to the histological examination of a calvarial mass after surgery. We also briefly review the literature.
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/J.WNEU.2012.12.018
Abstract: Endoscopy has provided a less invasive approach to skull base surgery, mainly through endonasal routes, but has been limited in its applications due to potential complications. The aims of this study were to evaluate the feasibility of the purely endoscopic extradural transcranial approach to lateral and central skull base through a subtemporal keyhole and to better understand potential distortions of the related anatomy via endoscopy. Ten fresh cadaver heads were studied with 4-mm 0° and 30° endoscopes to develop the surgical approach and to identify surgical landmarks. The endoscopic extradural subtemporal approach was ided into 3 sections after exposure of the extradural space in the middle cranial fossa: 1) exposure of the lateral wall of the cavernous sinus and the preauricular infratemporal fossa 2) anterior petrosectomy and posterior cranial fossa exploration and 3) unroofing of the tympanic cavity and exposure of the facial nerve. This keyhole endoscopic technique clearly visualized anatomical landmarks of the lateral and central skull base via an extradural subtemporal route. The endoscopic extradural subtemporal approach was feasible. This approach could display a wide range of lateral and central skull base structures with minimal invasiveness. The use of extradural space would be key to performing safe and effective endoscopic skull base surgery.
Publisher: Springer Science and Business Media LLC
Date: 17-10-2006
Publisher: Springer Science and Business Media LLC
Date: 10-02-2015
DOI: 10.1007/S10143-015-0613-7
Abstract: Transsphenoidal surgery in the setting of acromegaly is quite challenging due to increased soft tissue mass, bony overgrowth, and bleeding. There is a debate on the endoscopic versus microscopic approach for these patients. The purpose of our study is to compare the outcomes for acromegaly after transsphenoidal surgery using both techniques. Retrospective review of 65 acromegalic patients who underwent transsphenoidal surgery in our department. Clinical remission was defined as resolution of typical acromegalic symptoms. Radiological resection was defined by volumetric criteria, and biochemical remission was defined as by the 2010 consensus on the criteria for remission of acromegaly. There was no significant difference in age, preoperative endocrine status, percent of macro adenomas, suprasellar, or infrasellar extension between both groups. Patients were assigned to both groups based on our existing referral pattern. Endoscopic approach was performed in 42 patients, while the microscopic approach was performed in 23 patients. No significant difference in remission rates was found between both groups (45.2 vs. 34.7 %, p = 0.40). The endoscopic group, however, had a significantly higher rate of gross total resections (61 vs. 42 %, p = 0.05). There was also a trend towards higher rates of gross total resections when cavernous sinus was present (48 vs. 14.2 %, p = 0.09). Postoperative diabetes insipidus occurred more in microscopic patients (34.7 vs. 17 %, p = 0.05), otherwise there was no significant difference in rates of complications. The median follow-up period was 56.6 months (range 6-156, mean 66.1). There is no significant difference in the rates of biochemical remission between the endoscopic and microscopic techniques. The endoscope technique, however, seems to be superior in achieving gross total resection especially with tumors invading the cavernous sinus.
Publisher: Journal of Neurosurgery Publishing Group (JNSPG)
Date: 05-2011
DOI: 10.3171/2010.10.JNS101331
Abstract: Berengario da Carpi was one of the most famous physicians of the 16th century, a recognized master of anatomy and surgery, an emblematic “Renaissance man” who combined his medical experience and engineering knowledge to design new surgical instruments, and effectively used the arts of writing and drawing to describe state-of-the-art medicine and provide illustrations of anatomical structures. His greatest contribution to medicine was to write the most important work on craniocerebral surgery of the 16th century, the Tractatus de Fractura Calvae sive Cranei ( Treatise on Fractures of the Calvaria or Cranium ), in which he described an entire set of surgical instruments to be used for cranial operations to treat head traumas that became a reference for later generations of physicians. This was a systematic treatise covering the mechanisms, classification, and medical and surgical treatment of head traumas, and can be considered a milestone in the history of neurotraumatology.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2015
Publisher: Bioscientifica
Date: 04-2013
DOI: 10.1530/JME-13-0241
Abstract: Autophagy is an important cellular process involving the degradation of intracellular components. Its regulation is complex and while there are many methods available, there is currently no single effective way of detecting and monitoring autophagy. It has several cellular functions that are conserved throughout the body, as well as a variety of different physiological roles depending on the context of its occurrence in the body. Autophagy is also involved in the pathology of a wide range of diseases. Within the endocrine system, autophagy has both its traditional conserved functions and specific functions. In the endocrine glands, autophagy plays a critical role in controlling intracellular hormone levels. In peptide-secreting cells of glands such as the pituitary gland, crinophagy, a specific form of autophagy, targets the secretory granules to control the levels of stored hormone. In steroid-secreting cells of glands such as the testes and adrenal gland, autophagy targets the steroid-producing organelles. The dysregulation of autophagy in the endocrine glands leads to several different endocrine diseases such as diabetes and infertility. This review aims to clarify the known roles of autophagy in the physiology of the endocrine system, as well as in various endocrine diseases.
Publisher: Public Library of Science (PLoS)
Date: 02-12-2021
DOI: 10.1371/JOURNAL.PONE.0260717
Abstract: Eye-tracking research has been widely used in radiology applications. Prior studies exclusively analysed either temporal or spatial eye-tracking features, both of which alone do not completely characterise the spatiotemporal dynamics of radiologists’ gaze features. Our research aims to quantify human visual search dynamics in both domains during brain stimuli screening to explore the relationship between reader characteristics and stimuli complexity. The methodology can be used to discover strategies to aid trainee radiologists in identifying pathology, and to select regions of interest for machine vision applications. The study was performed using eye-tracking data 5 seconds in duration from 57 readers (15 Brain-experts, 11 Other-experts, 5 Registrars and 26 Naïves) for 40 neuroradiological images as stimuli (i.e., 20 normal and 20 pathological brain MRIs). The visual scanning patterns were analysed by calculating the fractal dimension (FD) and Hurst exponent (HE) using re-scaled range (R/S) and detrended fluctuation analysis (DFA) methods. The FD was used to measure the spatial geometrical complexity of the gaze patterns, and the HE analysis was used to measure participants’ focusing skill. The focusing skill is referred to persistence/anti-persistence of the participants’ gaze on the stimulus over time. Pathological and normal stimuli were analysed separately both at the “First Second” and full “Five Seconds” viewing duration. All experts were more focused and a had higher visual search complexity compared to Registrars and Naïves. This was seen in both the pathological and normal stimuli in the first and five second analyses. The Brain-experts subgroup was shown to achieve better focusing skill than Other-experts due to their domain specific expertise. Indeed, the FDs found when viewing pathological stimuli were higher than those in normal ones. Viewing normal stimuli resulted in an increase of FD found in five second data, unlike pathological stimuli, which did not change. In contrast to the FDs, the scanpath HEs of pathological and normal stimuli were similar. However, participants’ gaze was more focused for “Five Seconds” than “First Second” data. The HE analysis of the scanpaths belonging to all experts showed that they have greater focus than Registrars and Naïves. This may be related to their higher visual search complexity than non-experts due to their training and expertise.
Publisher: Elsevier BV
Date: 07-2021
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.WNEU.2019.09.040
Abstract: In the era of integrated genomic-histologic analysis of brain tumors, new biomarkers have been introduced as diagnostic, prognostic, and therapeutic indicators. The analysis of the mutation in the isocitrate dehydrogenase (IDH) genes IDH1 and IDH2 has provided important diagnostic and prognostic information for patients affected by diffuse glioma (i.e., the presence of the mutation has been related to an increased survival rate). The reference standard of IDH mutation detection has been its assessment in surgical specimens, immunohistochemistry, and/or genetic sequencing. Knowing the IDH status information preoperatively would be of great importance, because it has been related to tumor progression and the response to treatment. The oncometabolite 2-hydroxyglutarate (2HG), accumulated in gliomas with IDH mutation status, can be detected in vivo using magnetic resonance spectroscopy (MRS). The 2HG-MRS technique remains technically challenging. We have summarized the results of the first pilot study in Australia, which included 10 patients affected by glioma. The data recorded from May 2017 to November 2018 were analyzed. In our exploratory study, we reached a sensitivity and specificity of 100%, confirming the strong predictive role of 2HG, as detected using MRS, in the diagnosis of glioma. In the present study, we have focused on methodological tips and future perspectives of the technique in the neuroimaging and neuro-oncological scenario. We would advocate the integration of 2HG-MRS into standard clinical practice.
Publisher: Cold Spring Harbor Laboratory
Date: 25-04-2020
DOI: 10.1101/2020.04.24.060830
Abstract: Susceptibility-weighted imaging (SWI) is a technique useful for evaluation of the internal structures of brain tumors, including microvasculature and microbleeds. Intratumoral patterns of magnetic susceptibility can be quantified by means of fractal analysis. Here, we propose a radiomics methodological pipeline to merge advanced fractal-based computational modelling with statistical analysis to objectively characterize the fingerprint of gliomas and brain metastases. Forty-seven patients with glioma (grades II-IV, according to the WHO 2016 classification system) and fourteen with brain metastases underwent 3 Tesla MRI using a SWI protocol. All images underwent computational analysis aimed to quantify three Euclidean parameters (related to tumor and SWI volume) and five fractal-based parameters (related to the pixel distribution and geometrical complexity of the SWI patterns). Principal components analysis, linear and quadratic discriminant analysis, K-nearest neighbor and support vector machine methods were used to discriminate between tumor types. The combination of parameters offered an objective evaluation of the SWI pattern in gliomas and brain metastases. The model accurately predicted 88% of glioblastoma, according to the quantification of intratumoral SWI features, failing to discriminate the other types. SWI is not normally used to classify brain tumors, however fractal-based multi-parametric computational analysis can be used to characterize intratumoral SWI patterns to objectively quantify tumors-related features. Specific parameters still have to be identified to provide completely automatic computerized differential diagnosis.
Publisher: Springer Science and Business Media LLC
Date: 10-03-2012
DOI: 10.1007/S10143-012-0374-5
Abstract: Stereotactic biopsies represent a routine neurosurgical procedure for the diagnosis of intracranial lymphomas and selected diffusely infiltrating gliomas. Acquisition of tissue s les that do not allow correct tumor typing and grading is, however, not uncommon. Five-aminolevulinic acid (5-ALA) has been shown to accumulate in malignant tumor tissue. The aim of this study was to prospectively investigate the clinical usability of 5-ALA for intraoperative detection of representative tissue in stereotactic tumor biopsies. Fifty consecutive patients underwent frameless stereotactic biopsy for a suspected brain tumor. 5-ALA was administered 4 h before anesthesia. Serial biopsy s les were obtained and intraoperatively checked for 5-ALA fluorescence (strong, vague, or none) using a modified neurosurgical microscope. All s les were examined for the presence of representative tumor tissue according to neuroimaging (MRI, positron emission tomography, and/or chemical shift imaging) and histopathological parameters. Visible 5-ALA fluorescence was observed in 43/50 patients (strong in 39 and vague fluorescence in four cases). At biopsy target, 52/53 s les of glioblastomas, 9/10 s les of gliomas grade III, and 14/16 s les of lymphomas revealed strong 5-ALA fluorescence. S les with strong 5-ALA fluorescence were only observed at, but not outside the biopsy target. All tissue s les with strong 5-ALA fluorescence were representative according to our neuroimaging and histopathological criteria (positive predictive value of 100%). Our data indicate that strong 5-ALA fluorescence is a reliable and immediately available intraoperative marker of representative tumor tissue of malignant gliomas and intracranial lymphomas in stereotactic biopsies. Thereby, the application of 5-ALA in stereotactic brain tumor biopsies may in future reduce costs for operating room and neuropathology and may decrease procedure-related morbidity.
Publisher: Springer Science and Business Media LLC
Date: 26-01-2021
Publisher: Elsevier BV
Date: 12-2014
DOI: 10.1016/J.WNEU.2014.09.005
Abstract: Neuroendoscopy has become a well-accepted technique in neurosurgery. After the introduction of the endoscope in medical practice by Phillip Bozzini in 1806, influential in iduals such as Harold Hopkins and Karl Storz paved the way for its current success. With the present pace of technologic advancements, great improvement in the instrumentation is expected along with the status of neuroendoscopy in the neurosurgical field. Specific attention is given to the history of the development of the endoscope, while also discussing more recent advances dating from 1990 onward. The importance of each development for the purpose of the instrument is explained. Gaps in the literature regarding the technical aspects of neuroendoscopy, including the optical physics in the endoscope, three-dimensional endoscopy, and clinical applications of neuroendoscopy and robotics, are addressed.
Publisher: SAGE Publications
Date: 12-2014
Abstract: Validated trauma classification systems are the sole means to provide the basis for reliable documentation and evaluation of patient care, which will open the gateway to evidence-based procedures and healthcare in the coming years. With the support of AO Investigation and Documentation, a classification group was established to develop and evaluate a comprehensive classification system for craniomaxillofacial (CMF) fractures. Blueprints for fracture classification in the major constituents of the human skull were drafted and then evaluated by a multispecialty group of experienced CMF surgeons and a radiologist in a structured process during iterative agreement sessions. At each session, surgeons independently classified the radiological imaging of up to 150 consecutive cases with CMF fractures. During subsequent review meetings, all discrepancies in the classification outcome were critically appraised for clarification and improvement until consensus was reached. The resulting CMF classification system is structured in a hierarchical fashion with three levels of increasing complexity. The most elementary level 1 simply distinguishes four fracture locations within the skull: mandible (code 91), midface (code 92), skull base (code 93), and cranial vault (code 94). Levels 2 and 3 focus on further defining the fracture locations and for fracture morphology, achieving an almost in idual mapping of the fracture pattern. This introductory article describes the rationale for the comprehensive AO CMF classification system, discusses the methodological framework, and provides insight into the experiences and interactions during the evaluation process within the core groups. The details of this system in terms of anatomy and levels are presented in a series of focused tutorials illustrated with case ex les in this special issue of the Journal.
Publisher: Springer Science and Business Media LLC
Date: 18-08-2013
DOI: 10.1007/S00234-012-1081-1
Abstract: Susceptibility-weighted imaging (SWI) with high- and ultra-high-field magnetic resonance is a very helpful tool for evaluating brain gliomas and intratumoral structures, including microvasculature. Here, we test whether objective quantification of intratumoral SWI patterns by applying fractal analysis can offer reliable indexes capable of differentiating glial tumor grades. Thirty-six patients affected by brain gliomas (grades II-IV, according to the WHO classification system) underwent MRI at 7 T using a SWI protocol. All images were collected and analyzed by applying a computer-aided fractal image analysis, which applies the fractal dimension as a measure of geometrical complexity of intratumoral SWI patterns. The results were subsequently statistically correlated to the histopathological tumor grade. The mean value of the fractal dimension of the intratumoral SWI patterns was 2.086 ± 0.413. We found a trend of higher fractal dimension values in groups of higher histologic grade. The values ranged from a mean value of 1.682 ± 0.278 for grade II gliomas to 2.247 ± 0.358 for grade IV gliomas (p = 0.013) there was an overall statistically significant difference between histopathological groups. The present study confirms that SWI at 7 T is a useful method for detecting intratumoral vascular architecture of brain gliomas and that SWI pattern quantification by means of fractal dimension offers a potential objective morphometric image biomarker of tumor grade.
Publisher: Springer Science and Business Media LLC
Date: 27-11-2022
DOI: 10.1007/S00234-021-02845-1
Abstract: To systematically review the literature regarding the application of machine learning (ML) of magnetic resonance imaging (MRI) radiomics in common sellar tumors. To identify future directions for application of ML in sellar tumor MRI. PubMed, Medline, Embase, Google Scholar, Scopus, ArxIV, and bioRxiv were searched to identify relevant studies published between 2010 and September 2021. Studies were included if they specifically involved ML of MRI radiomics in the analysis of sellar masses. Risk of bias assessment was performed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) Tool. Fifty-eight articles were identified for review. All papers utilized retrospective data, and a quantitative systematic review was performed for thirty-one studies utilizing a public dataset which compared pituitary adenomas, meningiomas, and gliomas. One of the analyzed architectures yielded the highest classification accuracy of 0.996. The remaining twenty-seven articles were qualitatively reviewed and showed promising findings in predicting specific tumor characteristics such as tumor consistency, Ki-67 proliferative index, and post-surgical recurrence. This review highlights the potential clinical application of ML using MRI radiomic data of the sellar region in diagnosis and predicting treatment outcomes. We describe future directions for practical application in the clinical care of patients with pituitary neuroendocrine and other sellar tumors.
Publisher: Informa UK Limited
Date: 21-04-2022
DOI: 10.1080/02688697.2022.2064428
Abstract: Mental nerve stimulation is recognised as a treatment option for neuropathic facial pain. Historically however, lead migration across the mobile temporomandibular joint has prevented this procedures utility. We describe a new method of insertion and anchoring of a mental nerve stimulator for the management of refractory neuropathic pain in the distribution of the mental nerve. We anchored the stimulator lead to the mandibular body. Significant analgesic effect was achieved and no lead migration had occurred at 1 year post-operatively. This report describes in detail the procedure of mental nerve stimulator insertion, with a novel technique of mandibular anchoring of the lead.
Publisher: Elsevier BV
Date: 2015
DOI: 10.1016/J.CORTEX.2014.06.016
Abstract: In the eighteenth century, Lancisi described the indusium griseum (IG) and the longitudinal striae (LS) of the corpus callosum. The IG is a thin neuronal lamina above the corpus callosum, covered on each side of the midline by the medial and lateral LS. The medial LS (nerves of Lancisi) and lateral LS are two pairs of myelinated fiber bands found in the gray matter of the IG on the dorsal aspect of the corpus callosum. Embryologically, the IG and LS are dorsal remnants of the archicortex of the hippoc us and fornix and thus they are considered components of the limbic system. Recent studies using immunohistochemistry reported that acetylcholine, dopamine, noradrenaline, 5-hydroxytryptamine and GABA neurons innervate the IG. Newer imaging techniques, such as high field MRI and diffusion tensor imaging, provide new tools for studying these structures, whose true function remains still unclear. The present paper reviews the history of the discovery of the IG and LS of the corpus callosum, with a holistic overview on these interesting structures from the anatomical, embryological, neurochemical, radiological and clinical perspective.
Publisher: Wiley
Date: 05-2021
DOI: 10.1111/ANS.16843
Publisher: Springer Science and Business Media LLC
Date: 09-10-2023
Publisher: Elsevier BV
Date: 03-2015
DOI: 10.1016/J.ECL.2014.10.008
Abstract: Aggressive pituitary adenomas have a high risk of recurrence, a lack of therapeutic response, and resistance to conventional treatment. So far, no satisfactory biomarkers are available for predicting their behavior. Some specific pituitary adenoma histotypes are more prone to follow an aggressive behavior. Pituitary carcinomas are rare and show cerebrospinal and/or systemic metastasis. They have worse prognosis than aggressive adenomas, and radiation is of limited use in their treatment.
Publisher: Springer Science and Business Media LLC
Date: 17-04-2014
DOI: 10.1007/S00381-014-2411-X
Abstract: The skull base represents a central and complex bone structure of the skull and forms the floor of the cranial cavity on which the brain lies. Anatomical knowledge of this particular region is important for understanding several pathologic conditions as well as for planning surgical procedures. Embryology of the cranial base is of great interest due to its pronounced impact on the development of adjacent regions including the brain, neck, and craniofacial skeleton. Information from human and comparative anatomy, anthropology, embryology, surgery, and computed modelling was integrated to provide a perspective to interpret skull base formation and variability within the cranial functional and structural system. The skull base undergoes an elaborate sequence of development stages and represents a key player in skull, face and brain development. Furthering our holistic understanding of the embryology of the skull base promises to expand our knowledge and enhance our ability to treat associated anomalies.
Publisher: Incessant Nature Science Publishers Pvt Ltd.
Date: 2020
Publisher: Springer Science and Business Media LLC
Date: 13-02-2020
Publisher: The Endocrine Society
Date: 11-2022
DOI: 10.1210/JENDSO/BVAC150.1008
Abstract: Pituitary apoplexy [PA] is defined as an infarction, haemorrhage, or both within the pituitary gland, and can be life threatening. (Onesti 1990) Typically, it presents with sudden onset headache, visual changes, loss of consciousness and potentially life-threatening panhypopituitarism. If so, it is defined as a 'clinical' PA. In absence of these symptoms, it is defined as a 'subclinical' PA. (Kim 2009) Subclinical PA occurs more frequently than clinical PA. (Kim 2009 Möller-Goede 2011 Liu 2010 Cinar 2013) The rationale for this is still unclear. Tumour size, site of invasion, and cystic degeneration are all risk factors for apoplexy. (Biousse 2001 Boellis 2014)It is important to understand whether these factors differ between these groups to understand why subclinical apoplexy is more common, and to improve prevention and treatment. To identify whether underlying pituitary adenoma tumour size (width mm), site of invasion, or presence of cystic degeneration differed between clinical and subclinical populations with pituitary apoplexy (PA). Study design: This is a quantitative retrospective cohort study of patients attending Macquarie University Endocrinology Clinic and Macquarie Medical Imaging between 2011-2021. Clinical and subclinical patients were ided based on the acuity of their presentation (clinical = sudden onset headache, nausea, vomiting, visual changes, subclinical = gradual onset, or lack of symptoms). Adenomas & 10mm were classified as macroadenomas and & mm were microadenomas. Age, gender, presence of suprasellar extension, intrasellar invasion, lateral invasion, and cystic change were identified from neurosurgeon and neuroradiologist cross-reporting on MRI. 18 patients were included in the study aged between 19 years to 85 years with 13 females and 5 males. 55.6% presented subclinical and 44.4% clinically. 15 (83%) had macroadenomas and 3 (16%) had microadenomas. There were no significant differences in age, gender, width of adenoma, site of invasion, or presence of cystic degeneration between the two cohorts. However, the data supported previous literature which suggests that clinical pituitary apoplexy patients tend to have marginally larger adenomas and are more commonly associated with cystic degeneration. Overall, this study highlights potential differences in tumour size and presence of cystic degeneration between subclinical and clinical apoplexy patients. However, further research is required with a larger cohort to determine the significance of these differences. The critical demarcation of the underlying pathology between patients experiencing subclinical versus clinical PA is not yet clear in the literature to date. When haemorrhage is secondary to an underlying lesion, regrowth of the pituitary tumour years after an episode may occur, and patients may require long-term clinical and imaging surveillance. Therefore, the importance of these research findings is that it may allow for increased predictability and prevention of pituitary apoplexy, which can be a life-threatening event. Presentation: No date and time listed
Publisher: Journal of Neurosurgery Publishing Group (JNSPG)
Date: 07-08-2023
DOI: 10.3171/CASE23286
Abstract: The supplementary motor area (SMA) is essential in facilitating the commencement and coordination of complex self-initiated movements. Its complex functional connectivity poses a great risk for postoperative neurological deterioration. SMA syndrome can occur after tumor resection and comprises hemiakinesia and akinetic mutism (often, but unpredictably temporary). Although awake surgery is preferred for mapping and monitoring eloquent areas, connectomics is emerging as a novel technique to tailor neurosurgical approaches and predict functional prognosis, as illustrated in this case. The authors report on a patient presenting with recurrent oligodendroglioma after subtotal resection 7 years earlier. After extensive neuropsychological and neuroradiological assessment (including connectomics), awake surgery was indicated. No intraoperative deficits were recorded however, the patient presented with postoperative right-sided akinesia and mutism. Postoperative neuroimaging demonstrated the connectome overlapping the preoperative one, and indeed, neurological symptoms resolved after 3 days. Comparison of the pre- and postoperative connectome can be used to objectively evaluate surgical outcomes and assess patient prognosis. To the best of the authors’ knowledge, this is the first case demonstrating the feasibility of quantitative functional connectivity analysis as a prognostic tool for neurological improvement after surgery. A better understanding of brain networks is instrumental for improving diagnosis, prognosis, and treatment of neuro-oncological patients.
Publisher: Elsevier BV
Date: 12-2010
DOI: 10.1016/J.MVR.2010.09.005
Abstract: Normal brain parenchyma has a highly complex microvascular structure that undergoes re-modelling in the presence of a tumor. A detailed understanding of the clinical and pathological aspects of neo-angiogenesis in malignant human brain tumors is essential in order to ensure the successful clinical application of anti-angiogenic therapy. As the quantification of various aspects of tumor vasculature may provide an indication of angiogenic activity, it is reasonable to assume that identifying specific new biomarkers will help investigators to design more appropriate and less toxic anti-angiogenic treatment strategies. Research into the quantitative analysis of microangioarchitectures can be ided into two main branches: morphometrics and biomarker research. Morphometrics adds quantitative elements to the qualitative description of tissues by means of Euclidean and fractal geometrical parameters, whereas biomarker research seeks predictors that can be used in clinical applications. All of the many morphometric parameters used to analyze microvascular networks in brain tumors have their pros and cons, but none has yet been validated as a reliable biomarker. This review describes the helpfulness and limitations of the morphometric parameters that have so far been proposed, and the current "state-of-the-art" in planning future research into biomarkers and morphometry of the microangioarchitecture of brain tumors. It concludes by discussing the need to make a multiparametric analysis of histological specimens that can be integrated with qualitative and quantitative analyses based on neuroradiological and nuclear medicine techniques in order to provide a valid holistic representation of brain tumors. An empirical algorithm for assessing the microangioarchitecture of brain tumors is also provided.
Publisher: Journal of Neurosurgery Publishing Group (JNSPG)
Date: 03-2018
DOI: 10.3171/2016.10.JNS161825
Abstract: Quantitative assessment of tumor microvascularity has the potential to improve prognostication, advance understanding of tumor biology, and help narrow potential molecular therapies. While the role of tumor microvascularity has been widely studied in meningiomas, this study examines both the role of automated measurements and the impact on surgical outcome. Two hundred seven patients with Grade I meningiomas underwent surgery between 1996 and 2011. Tissue s les from each patient were retrospectively evaluated for histopathological measures of microvascularity, including staining for von Willebrand factor (vWF), CD31, CD105, hypoxia-inducible factor 1 (HIF-1), vascular endothelial growth factor, glucose transporter 1, and carbonic anhydrase IX. Manual methods of assessing microvascularity were supplemented by a computational analysis of the microvascular patterns by means of fractal analysis. MIB-1 proliferation staining was also performed on the same tumors. These measures were compared with various patient characteristics, tumor volume, estimated blood loss (EBL) during surgery, progression-free survival (PFS), and overall survival (OS). The mean patient age was 55.4 ± 14.8 years, and 63 (30.4%) patients were male. Patients harboring tumors ≥ 3 cm were significantly older (56.9 ± 15.2 years vs 53.1 ± 13.6 years p = 0.07), more frequently male (40.8% vs 14.6% p = 0.0001), and had greater EBL (446.5 ± 532.2 ml vs 185.4 ± 197.2 ml p = 0.0001), greater tumor volume (33.9 ± 38.1 ml vs 29.4 ± 23.5 ml p = 0.0001), higher MIB-1 index values (3.0% ± 5.4% vs 1.7% ± 1.7% p = 0.03), higher vWF levels (85.6% ± 76.9% vs 54.1% ± 52.4% p = 0.001), lower HIF-1 expression (1.4 ± 1.3 vs 2.2 ± 1.4 p = 0.004), and worse OS (199.9 ± 7.6 months vs 180.8 ± 8.1 months p = 0.05) than patients with tumors 3 cm. In the multivariate logistic regression, MIB-1 (OR 1.14 p = 0.05), vWF (OR 1.01 p = 0.01), and HIF-1 (OR 1.54 p = 0.0001) significantly predicted tumor size. Although multiple factors were predictive of EBL in the univariate linear regression, only vWF remained significant in the multivariate analysis (β = 0.39 p = 0.004). Lastly, MIB-1 was useful via Kaplan-Meier survival analysis for predicting patients with disease progression, whereby an MIB-1 cutoff value of ≥ 3% conferred a 36% sensitivity and 82.5% specificity in predicting disease progression an MIB-1 value ≥ 3% showed significantly shorter mean PFS (140.1 ± 11.7 months vs 179.5 ± 7.0 months log-rank test, p = 0.05). The Cox proportional hazards model showed a trend for MIB-1 in predicting disease progression in a hazards model (OR 1.08 95% CI 0.99–1.19 p = 0.08). These results support the importance of various microvascularity measures in predicting preoperative (e.g., tumor size), intraoperative (e.g., EBL), and postoperative (e.g., PFS and OS) outcomes in patients with Grade I meningiomas. An MIB-1 cutoff value of 3% showed good specificity for predicting tumor progression. The predictive ability of various measures to detect aberrant tumor microvasculature differed, possibly reflecting the heterogeneous underlying biology of meningiomas. It may be necessary to combine assays to understand angiogenesis in meningiomas.
Location: Germany
Location: No location found
Location: Italy
Location: Italy
Start Date: 2020
End Date: 12-2023
Amount: $1,015,000.00
Funder: Australian Research Council
View Funded Activity