ORCID Profile
0000-0002-4780-0393
Current Organisation
The University of Newcastle
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Publisher: MDPI AG
Date: 06-06-2019
DOI: 10.3390/NU11061285
Abstract: Few studies have investigated the underlying neural substrates of food addiction (FA) in humans using a recognised assessment tool. In addition, no studies have investigated subregions of the amygdala (basolateral (BLA) and central amygdala), which have been linked to reward-seeking behaviours, susceptibility to weight gain, and promoting appetitive behaviours, in the context of FA. This pilot study aimed to explore the association between FA symptoms and activation in the BLA and central amygdala via functional magnetic resonance imaging (fMRI), in response to visual food cues in fasted and fed states. Females (n = 12) aged 18–35 years completed two fMRI scans (fasted and fed) while viewing high-calorie food images and low-calorie food images. Food addiction symptoms were assessed using the Yale Food Addiction Scale. Associations between FA symptoms and activation of the BLA and central amygdala were tested using bilateral masks and small-volume correction procedures in multiple regression models, controlling for BMI. Participants were 24.1 ± 2.6 years, with mean BMI of 27.4 ± 5.0 kg/m2 and FA symptom score of 4.1 ± 2.2. A significant positive association was identified between FA symptoms and higher activation of the left BLA to high-calorie versus low-calorie foods in the fasted session, but not the fed session. There were no significant associations with the central amygdala in either session. This exploratory study provides pilot data to inform future studies investigating the neural mechanisms underlying FA.
Publisher: SAGE Publications
Date: 18-11-2013
DOI: 10.1111/IJS.12214
Publisher: SAGE Publications
Date: 21-07-2017
Abstract: Focal hyperperfusion after acute ischaemic stroke could be of prognostic value depending upon its spatial localisation and temporal dynamics. Factors associated with late stage (12–24 h) perilesional hyperperfusion, identified using arterial spin labelling, are poorly defined. A prospective cohort of acute ischaemic stroke patients presenting within 4.5 h of symptom onset were assessed with multi-modal computed tomography acutely and magnetic resonance imaging at 24 ± 8 h. Multivariate logistic regression analysis and receiver operating characteristics curves were used. One hundred and nineteen hemispheric acute ischaemic stroke patients (mean age = 71 ± 12 years) with 24 h arterial spin labelling imaging were included. Forty-two (35.3%) patients showed perilesional hyperperfusion on arterial spin labelling at 24 h. Several factors were independently associated with perilesional hyperperfusion: good collaterals (71% versus 29%, P 0.0001 OR = 5, 95% CI = [1.6, 15.7], P = 0.005), major reperfusion (81% versus 48%, P = 0.0001 OR = 7.5, 95% CI = [1.6, 35.1], P = 0.01), penumbral salvage (76.2% versus 47%, P = 0.002 OR = 6.6, 95% CI = [1.8, 24.5], P = 0.004), infarction in striatocapsular (OR = 9.5, 95% CI = [2.6, 34], P = 0.001) and in cortical superior ision middle cerebral artery (OR = 4.7, 95% CI = [1.4, 15.7], P = 0.012) territory. The area under the receiver operating characteristic curve was 0.91. Our results demonstrate good arterial collaterals, major reperfusion, penumbral salvage, and infarct topographies involving cortical superior middle cerebral artery and striatocapsular are associated with perilesional hyperperfusion.
Publisher: Radiological Society of North America (RSNA)
Date: 11-2015
Publisher: Elsevier BV
Date: 2020
Publisher: Elsevier BV
Date: 12-2014
DOI: 10.1016/J.MATH.2014.01.006
Abstract: Evidence is emerging for central nervous system (CNS) changes in the presence of musculoskeletal dysfunction and pain. Motor control exercises, and potentially manual therapy, can induce changes in the CNS, yet the focus in musculoskeletal physiotherapy practice is conventionally on movement impairments with less consideration of intervention-induced neuroplastic changes. Studies in healthy in iduals and those with neurological dysfunction provide ex les of strategies that may also be used to enhance neuroplasticity during the rehabilitation of in iduals with musculoskeletal dysfunction, improving the effectiveness of interventions. In this paper, the evidence for neuroplastic changes in patients with musculoskeletal conditions is discussed. The authors compare and contrast neurological and musculoskeletal physiotherapy clinical paradigms in the context of the motor learning principles of experience-dependent plasticity: part and whole practice, repetition, task-specificity and feedback that induces an external focus of attention in the learner. It is proposed that increased collaboration between neurological and musculoskeletal physiotherapists and researchers will facilitate new discoveries on the neurophysiological mechanisms underpinning sensorimotor changes in patients with musculoskeletal dysfunction. This may lead to greater integration of strategies to enhance neuroplasticity in patients treated in musculoskeletal physiotherapy practice.
Publisher: Georg Thieme Verlag KG
Date: 02-02-2016
Abstract: The National Rugby League (NRL) in Australia introduced a new 'concussion interchange rule' (CIR) in 2014, whereby a player suspected of having sustained a concussion can be removed from play, and assessed, without an interchange being tallied against the player's team. We conducted a video analysis, describing player and injury characteristics, situational factors, concussion signs, and return to play for each "CIR" event for the 2014 season. There were 167 reported uses of the CIR. Apparent loss of consciousness/unresponsiveness was observed in 32% of cases, loss of muscle tone in 54%, clutching the head in 70%, unsteadiness of gait in 66%, and a vacant stare in 66%. More than half of the players who were removed under the CIR returned to play later in the same match (57%). Most incidences occurred from a hit up (62%) and occurred during a tackle where the initial contact was with the upper body (80%). The new concussion interchange rule has been used frequently during the first season of its implementation. In many cases, there appeared to be video evidence of injury but the athlete was cleared to return to play. More research is needed on the usefulness of video review for identifying signs of concussive injury.
Publisher: Medknow
Date: 2017
Abstract: Epidemiological studies on the extent of the interaction and/or influence of stroke severity on clinical outcomes are important. The aim of the present study was to investigate the putative (and degree of) impact of initial stroke severity in predicting the overall functional outcome, in-hospital placement, and mortality in acute ischemic stroke (AIS) in comparison with age, admission to the stroke unit and thrombolytic treatment. The John Hunter Hospital acute stroke register was used to collect a retrospective cohort of AIS patients being assessed for reperfusion therapy and admitted between January 2006 and December 2013. Univariate and multivariate logistic regression and receiver operating characteristics analyses were used to assess associations with functional outcome, in-hospital placement, and mortality at 90 days. 608 AIS patients with complete datasets were included in the study. On univariate analysis, initial stroke severity showed the strongest independent association to the risk of death within 90 days (Odds ratio (OR) =1.15 P < 0.001 95% confidence interval (CI) = [1.11, 1.18]) age was a less significant independent influence (OR = 1.02 P = 0.049 95% CI = [1.00, 1.03]). Multivariate logistic regression analysis demonstrated that initial stroke severity independently predicted the 90 day mortality (OR = 1.16 95% CI = [1.12, 1.2] P < 0.0001) and unfavorable outcome (OR = 1.16 95% CI = [1.13, 1.2] P < 0.0001). Higher National Institute of Health Stroke Scale at admission was significantly associated with longer in-hospital placement (P < 0.0001). In this acute stroke cohort, initial stroke severity had a major impact on the likelihood of death following an AIS and appears to be the dominant influence on the overall stroke outcome and in-hospital placement.
Publisher: Mary Ann Liebert Inc
Date: 11-2012
Abstract: Sports-related concussion (SRC) is typically associated with functional, as opposed to structural, injury. The results of traditional structural neuroimaging techniques used to assess SRC tend to be normal in many athletes, and are only clinically helpful in ruling out a more serious injury. Diffusion tensor imaging (DTI) has increasingly been touted as a method offering greater clinical potential in mild traumatic brain injury (mTBI). Despite this, the utility of DTI as a clinical tool for diagnosing and managing SRC has received considerably less attention than it has in the general TBI research literature. The aim of this article is to conduct a systematic review of DTI in SRC, and to provide a focus and overview of research findings using this MRI technique in SRC. A systematic review of articles published in the English language, up to February 2012, was retrieved via PsycINFO(®), MEDLINE(®), EMBASE, SPORTDiscus(™), Scopus, Web of Science, and Informit using the key search terms: diffusion tensor imaging, diffusion magnetic resonance imaging, diffusion weighted MRI, diffusion MRI, fractional anisotropy, tractography, apparent diffusion coefficient, magnetic resonance imaging, mild traumatic brain injury, mTBI, traumatic brain injury, concussion, sport, athletic and athlete. Observational, cohort, correlation, cross-sectional and longitudinal studies were all included in the current review. Results of the review found eight articles that met inclusion criteria, which included data on 214 athletes and 96 controls. Seven of eight studies reported some type of DTI abnormality, although the neuroanatomical sites involved varied. Although considerable methodological variations exist across studies, the current review suggests that DTI may possess adequate diagnostic sensitivity to detect SRC in affected athletes. Further longitudinal studies are required to demonstrate its discriminate validity and prognostic capacity within this field.
Publisher: Radiological Society of North America (RSNA)
Date: 07-2008
Publisher: SAGE Publications
Date: 20-03-2022
DOI: 10.1177/02841851221080517
Abstract: Cerebral collateral status has a potential role in mediating postreperfusion clinical and safety outcomes in acute ischemic stroke (AIS). To investigate the prognostic accuracy and impact of collateral status on clinical and safety outcomes in patients with AIS receiving reperfusion therapy. Studies with AIS patients treated with reperfusion therapy, collateral status assessed using Tan, ASITN/SIR, or similar collateral grading methods and data stratified according to collateral status were included. Relevant data on clinical outcomes, such as functional outcome at 90 days, mortality at 90 days, angiographic reperfusion, symptomatic intracerebral hemorrhage (sICH) and hemorrhagic transformation (HT), were collated and analyzed. A meta-analysis of 18 studies involving 4132 patients with AIS was conducted. Good collateral status was significantly associated with angiographic reperfusion (odds ratio [OR]=1.97, 95% confidence interval [CI]=1.38–2.80 P 0.0001), sICH (OR=0.67, 95% CI=0.46–0.99 P = 0.042), and 90-day functional outcome (OR=3.05, 95% CI=1.78–5.24 P 0.0001). However, its association with HT (OR=0.76, 95% CI=0.38–1.51 P = 0.425) and three-month mortality (OR=0.53, 95% CI=0.17–1.69 P = 0.280) did not reach statistical significance. The prognostic accuracy of collaterals for predicting angiographic reperfusion, HT, functional outcome (at 90 days), and mortality (at 90 days) were 63%, 49%, 66%, and 48%, respectively. Cerebral collaterals are significantly associated with clinical and safety outcomes, albeit with a prognostic accuracy range of 48%–66% thus, evaluation of their patency is a useful prognostic tool in patients with AIS receiving reperfusion therapy.
Publisher: Radiological Society of North America (RSNA)
Date: 07-2011
DOI: 10.1148/RG.314105160
Abstract: Diffusion-weighted imaging provides a novel contrast mechanism in magnetic resonance (MR) imaging and has a high sensitivity in the detection of changes in the local biologic environment. A significant advantage of diffusion-weighted MR imaging over conventional contrast material-enhanced MR imaging is its high sensitivity to change in the microscopic cellular environment without the need for intravenous contrast material injection. Approaches to the assessment of diffusion-weighted breast imaging findings include assessment of these data alone and interpretation of the data in conjunction with T2-weighted imaging findings. In addition, the analysis of apparent diffusion coefficient (ADC) value can be undertaken either in isolation or in combination with diffusion-weighted and T2-weighted imaging. Most previous studies have evaluated ADC value alone however, overlap in the ADC values of malignant and benign disease has been observed. This overlap may be partly due to selection of b value, which can influence the concomitant effect of perfusion and emphasize the contribution of multicomponent model influences. The simultaneous assessment of diffusion-weighted and T2-weighted imaging data and ADC value has the potential to improve specificity. In addition, the use of diffusion-weighted imaging in a standard breast MR imaging protocol may heighten sensitivity and thereby improve diagnostic accuracy. Standardization of diffusion-weighted imaging parameters is needed to allow comparison of multicenter studies and assessment of the clinical utility of diffusion-weighted imaging and ADC values in breast evaluation.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2005
Publisher: Elsevier BV
Date: 03-2020
DOI: 10.1016/J.RADONC.2019.10.001
Abstract: To investigate the role of multi-parametric magnetic resonance imaging (MP-MRI) as a biomarker for squamous cell carcinoma of the anal canal (SCCAC). From January 2013 to January 2017, 25 patients with non-metastatic SCCAC were enrolled in a multi-centre prospective clinical trial, of whom 20 completed protocol treatment. MP-MRIs, incorporating diffusion weighted magnetic resonance imaging (DW-MRI) and dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) sequences, were performed before (baseline), during the second and fourth weeks of chemo-radiotherapy (CRT), and 8 weeks following treatment completion. Histogram analysis of multi-parametric maps generated maximum, mean, median, minimum, skewness, kurtosis, and standard deviation metrics. Exact logistic regression and ROC AUC analyses were performed for each metric at every timepoint. An elastic net LASSO logistic regression was also performed using all measures at each timepoint. With a median follow up of 17.1 months, 3/20 patients had a local recurrence, and 5/20 had any recurrence. Several apparent diffusion coefficient (ADC) metrics extracted from DW-MRIs correlated with local recurrence and demonstrated excellent discrimination: baseline skewness (p = 0.04, ROC AUC 0.90) and standard deviation (SD) (p = 0.02, ROC AUC 0.90), week 2 skewness (p = 0.02, ROC AUC 0.91) and SD (p = 0.01, ROC AUC 0.94), week 4 kurtosis (p = 0.01, AUC 0.92) and SD (p = 0.01, ROC AUC 0.96). Changes in minimum ADC between baseline and week 2 (p = 0.02, ROC AUC 0.94) and baseline and week 4 (p = 0.02, ROC AUC 0.94) were prognostic for local recurrence. For prediction of any recurrence, ADC minimum (p = 0.02, ROC AUC 0.87) and SD (p = 0.01, ROC AUC 0.85) at baseline, and ADC maximum (p = 0.03, ROC AUC 0.77) and SD (p = 0.02, ROC AUC 0.81) at week 4 were significant. On LASSO logistic regression, ADC minimum and SD at baseline were retained for any recurrence. The only significant finding for DCE-MRI was a correlation of k-trans min at the second follow-up with local recurrence (p = 0.05, AUC 0.84). Several ADC parameters at various time points correlate with recurrence suggesting DW-MRI is a potential biomarker for SCCAC.
Publisher: Springer Berlin Heidelberg
Date: 2006
DOI: 10.1007/11866763_113
Abstract: This paper considers the problem of automatic classification of textured tissues in 3D MRI. More specifically, it aims at validating the use of features extracted from the phase of the MR signal to improve texture discrimination in bone segmentation. This extra information provides better segmentation, compared to using magnitude only features. We also present a novel multiscale scheme to improve the speed of pixel based classification algorithm, such as support vector machines. This algorithm dramatically increases the speed of the segmentation process by an order of magnitude through a reduction of the number of pixels that needs to be classified in the image.
Publisher: Elsevier BV
Date: 03-2005
DOI: 10.1016/J.EJRAD.2004.03.016
Abstract: In vivo magnetic resonance (MR) spectroscopy at 1.5T was performed on a large polypoid cutaneous melanoma, and two enlarged lymph nodes containing metastatic melanoma, from three patients. Spectra were acquired in vivo from voxels wholly within the primary tumour or secondary lymph node and were thus uncontaminated by signals from adjacent tissue. Tissue biopsies taken after resection of primary tumours and secondary lymph nodes were examined by 8.5T magnetic resonance spectroscopy (MRS) and the results compared with the in vivo spectra, and with spectra from normal skin and a benign skin lesion. There was good agreement between the dominant features of 1.5T spectra acquired in vivo and 8.5T spectra acquired from resected tissue. However, less intense resonances observed at 8.5T in malignant biopsy tissue were not consistently observed at 1.5T in vivo. In vivo spectra from primary and metastatic melanoma showed high levels of choline metabolites. An intense lactate resonance was also present in the in vivo spectrum of primary melanoma. All 8.5T spectra of biopsies from primary and secondary melanoma showed high levels of choline metabolites and lactate, and additional resonances consistent with elevated levels of taurine, alanine, lysine, and glutamate/glutamine relative to normal and benign tissue. Elevated levels of choline, lactate, taurine, and amino acids appear to be clinically useful markers for identifying the pathology of primary and metastatic melanoma.
Publisher: Wiley
Date: 04-10-2013
DOI: 10.1002/NBM.3045
Publisher: Elsevier BV
Date: 08-2007
DOI: 10.1016/J.MEDIA.2007.03.003
Abstract: Magnetic resonance (MR) imaging is a widely available and well accepted non invasive imaging technique. Development of automatic and semi-automatic techniques to analyse MR images has been the focus of much research and numerous publications. However, most of this research only uses the magnitude of the acquired complex MR signal, discarding the phase information. In MR, the phase relates to the magnetic properties of tissues, information which is not found in the magnitude signal. As a result, phase is a complement to the magnitude signal and can improve the segmentation and analysis of MR images. In this paper, we consider the automatic classification of textured tissues in 3D MRI. Specifically, we include features extracted from the phase of the MR signal to improve texture discrimination in the bone segmentation. Our approach does not require phase unwrapping, with the MR signal processed in its complex form. The extra information extracted from the phase provides better segmentation, compared to only using magnitude features. The segmentation approach is integrated within a novel multiscale scheme, designed to improve the speed of pixel based classification algorithms, such as support vector machines. An order of magnitude increase is obtained, by reducing the number of pixels that need to be classified.
Publisher: SAGE Publications
Date: 20-07-2017
Abstract: Evaluation of the venous system may be useful in stroke prognostication and patient selection for acute intervention strategies. We report a novel phenomenon, delayed-late venous phase cortical vein filling, observed on dynamic computed tomography angiography obtained using multidetector computed tomography scanner, in acute ischemic stroke patients. The aim of this study was to examine the frequency of delayed-late venous phase cortical vein filling and assess its association to baseline collateral status. Dynamic computed tomography angiography images of acute ischemic stroke patients, being assessed for reperfusion therapy, were prospectively studied. Delayed-late venous phase cortical vein filling was defined by late venous phase opacification of cortical veins despite contrast clearance from contralateral cortical veins on dynamic computed tomography angiography. Time to peak of maximum arterial enhancement was recorded. A total of 117 patients (mean age = 70.6 ± 13.3 years males = 48%) with hemispheric ischemic stroke who underwent acute dynamic computed tomography angiography were included in the study. Overall, 56 (48%) demonstrated delayed-late venous phase cortical vein filling. Poor collateralization (OR = 13.50 95% CI = (4.2, 43) p ≤ 0.0001) and longer time to peak of maximum arterial enhancement (OR = 3.2 95% CI = (1.96, 5.3) p ≤ 0.0001) were positively associated with delayed-late venous phase cortical vein filling. Delayed-late venous phase cortical vein filling was independently associated with poor baseline collateral status (75% vs. 15%, p ≤ 0.0001 OR = 14.38 95% CI = (4.33, 47.8) p ≤ 0.0001). Delayed-late venous phase cortical vein filling is frequently seen in patients with acute ischemic stroke and is associated with poor baseline collateralization.
Publisher: JMIR Publications Inc.
Date: 07-01-2014
DOI: 10.2196/JMIR.2909
Publisher: MDPI AG
Date: 21-10-2014
DOI: 10.3390/NU6104552
Publisher: Wiley
Date: 2009
DOI: 10.1002/NBM.1301
Abstract: Information for determining whether a primary breast lesion is invasive and its receptor status and grade can be obtained before surgery by performing proton MRS on a fine-needle aspiration biopsy (FNAB) specimen and analyzing the MRS information by a pattern recognition method. Two-dimensional MRS, on either specimens or cells, allows the unambiguous assignment of most resonances. When correlated with the spectral regions selected by the pattern recognition method, there are strong indications for the biochemical markers responsible for prognostic information of invasive capacity and metastatic spread. Spectral assignments and biological correlations can be made using cell models. In vivo MRS can distinguish invasive from benign lesions. This pathological distinction can be made from the presence of resonances at discrete frequencies. To achieve this level of spectral resolution and signal-to-noise ratio, there are stringent requirements when acquiring and processing the data. The challenge now is to implement two-dimensional MRS in vivo. Until this is realized, the combination of in vivo MR, for diagnosis and spatial location, and MRS, for image-guided biopsy to provide information on tumor spread, promises to provide a higher level of preoperative diagnosis than previously achieved.
Publisher: Mary Ann Liebert Inc
Date: 2014
Abstract: Traditional structural neuroimaging techniques are normal in athletes who sustain sport-related concussions and are only considered to be clinically helpful in ruling out a more serious brain injury. There is a clinical need for more sophisticated, non-invasive imaging techniques capable of detecting changes in neurophysiology after injury. Concussion is associated with neurometabolic changes including neuronal depolarization, release of excitatory neurotransmitters, ionic shifts, changes in glucose metabolism, altered cerebral blood flow, and impaired axonal function. Proton magnetic resonance spectroscopy ((1)H-MRS, or simply MRS) is capable of measuring brain biochemistry and has the potential to identify and quantify physiologic changes after concussion. The focus of the current review is to provide an overview of research findings using MRS in sport-related concussion. A systematic review of articles published in the English language, up to February 2013, was conducted. Articles were retrieved via the databases: PsychINFO, Medline, Embase, SportDiscus, Scopus, Web of Science, and Informit using key terms: magnetic resonance spectroscopy, nuclear magnetic resonance spectroscopy, neurospectroscopy, spectroscopy, two-dimensional nuclear magnetic resonance spectroscopy, correlation spectroscopy, J-spectroscopy, exchange spectroscopy, nuclear overhauser effect spectroscopy, NMR, MRS, COSY, EXSY, NOESY, 2D NMR, craniocerebral trauma, mild traumatic brain injury, mTBI, traumatic brain injury, brain concussion, concussion, brain damage, sport, athletic, and athlete. Observational, cohort, correlational, cross-sectional, and longitudinal studies were all included in the current review. The review identified 11 publications that met criteria for inclusion, comprised of data on 200 athletes and 116 controls. Nine of 11 studies reported a MRS abnormality consistent with an alteration in neurochemistry. The results support the use of MRS as a research tool for identifying altered neurophysiology and monitoring recovery in adult athletes, even beyond the resolution of post-concussive symptoms and other investigation techniques returning to normative levels. Larger cross-sectional, prospective, and longitudinal studies are needed to understand the sensitivity and prognostic value of MRS within the field of sport-related concussion.
Publisher: Mary Ann Liebert Inc
Date: 15-08-2020
Publisher: Wiley
Date: 08-2003
Publisher: BMJ
Date: 12-2014
DOI: 10.1136/BJSPORTS-2014-093901
Abstract: Traumatic brain injury influences regulation of cerebral blood flow in animal models and in human studies. We reviewed the use of transcranial Doppler ultrasound (US) to monitor cerebrovascular reactivity following sport-related concussion. A narrative and systematic review of articles published in the English language, from December 1982 to October 2013. Articles were retrieved via numerous databases using relevant key terms. Observational, cohort, correlational, cross-sectional and longitudinal studies were included. Three publications met the criteria for inclusion these provided data from 42 athletes and 33 controls. All three studies reported reductions in cerebrovascular reactivity via transcranial Doppler US. These initial results support the use of cerebrovascular reactivity as a research tool for identifying altered neurophysiology and monitoring recovery in adult athletes. Larger cross-sectional, prospective and longitudinal studies are required to understand the sensitivity and prognostic value of cerebrovascular reactivity in sport-related concussion.
Publisher: American Roentgen Ray Society
Date: 08-2010
DOI: 10.2214/AJR.09.3519
Publisher: Oxford University Press (OUP)
Date: 29-01-2013
DOI: 10.1111/NURE.12005
Abstract: There is increasing interest regarding the potential health effects of energy drink (ED) consumption. The aim of the present review was to investigate the existing evidence on health outcomes associated with ED consumption. Studies published between 1966 and February 2011 were retrieved and included if they met the following criteria: were randomized or pseudo randomized control trials studied a human population reported a health-related measure and investigated a whole ED (as opposed to in idual ingredients). Study quality was evaluated and data extracted using standardized tools. Fifteen studies were identified, the majority of which had less than 30 participants and included a short term of follow-up (range: 30 min-3 h). The following outcome measures were included: cardiorespiratory effects, physiological measures, pathological measures, and body composition. The mean dosage of ED was 390 mL (range: 250-750 mL). Commercial ED funding and/or study associations were identified in six studies. Studies investigating long-term consumption and follow-up were lacking. The findings from this review do not allow definitive dietary recommendations to be made regarding safe levels of ED consumption caution should be exercised when consuming these drinks until further high-quality research is undertaken to substantiate findings.
Publisher: Wiley
Date: 03-2015
Abstract: The purpose of this study was to investigate performance of the couch and coil mounts designed for MR-simulation prostate scanning using data from ten volunteers. Volunteers were scanned using the standard MR scanning protocol with the MR coil directly strapped on the external body and the volunteer lying on the original scanner table. They also were scanned using a MR-simulation table top and pelvic coil mounts. MR images from both setups were compared in terms of body contour variation and image quality effects within particular organs of interest. Six-field conformal plans were generated on the two images with assigned bulk density for dose calculation. With the MR-simulation devices, the anterior skin deformation was reduced by up to 1.7 cm. The hard tabletop minimizes the posterior body deformation which can be up to 2.3 cm on the standard table, depending on the weight of volunteer. The image signal-to-noise ratio reduced by 14% and 25% on large field of view (FOV) and small FOV images, respectively, after using the coil mount the prostate volume contoured on two images showed difference of 1.05 ± 0.66 cm3. The external body deformation caused a mean dose reduction of 0.6 ± 0.3 Gy, while the coverage reduced by 22% ± 13% and 27% ± 6% in V98 and V100, respectively. A dedicated MR simulation setup for prostate radiotherapy is essential to ensure the agreement between planning anatomy and treatment anatomy. The image signal was reduced after applying the coil mount, but no significant effect was found on prostate contouring.
Publisher: Elsevier
Date: 2013
Publisher: SPIE
Date: 26-02-2009
DOI: 10.1117/12.812460
Publisher: Springer Science and Business Media LLC
Date: 16-01-2018
Publisher: Wiley
Date: 06-04-2016
DOI: 10.1118/1.4944871
Abstract: The feasibility of radiation therapy treatment planning using substitute computed tomography (sCT) generated from magnetic resonance images (MRIs) has been demonstrated by a number of research groups. One challenge with an MRI-alone workflow is the accurate identification of intraprostatic gold fiducial markers, which are frequently used for prostate localization prior to each dose delivery fraction. This paper investigates a template-matching approach for the detection of these seeds in MRI. Two different gradient echo T1 and T2* weighted MRI sequences were acquired from fifteen prostate cancer patients and evaluated for seed detection. For training, seed templates from manual contours were selected in a spectral clustering manifold learning framework. This aids in clustering "similar" gold fiducial markers together. The marker with the minimum distance to a cluster centroid was selected as the representative template of that cluster during training. During testing, Gaussian mixture modeling followed by a Markovian model was used in automatic detection of the probable candidates. The probable candidates were rigidly registered to the templates identified from spectral clustering, and a similarity metric is computed for ranking and detection. A fiducial detection accuracy of 95% was obtained compared to manual observations. Expert radiation therapist observers were able to correctly identify all three implanted seeds on 11 of the 15 scans (the proposed method correctly identified all seeds on 10 of the 15). An novel automatic framework for gold fiducial marker detection in MRI is proposed and evaluated with detection accuracies comparable to manual detection. When radiation therapists are unable to determine the seed location in MRI, they refer back to the planning CT (only available in the existing clinical framework) similarly, an automatic quality control is built into the automatic software to ensure that all gold seeds are either correctly detected or a warning is raised for further manual intervention.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2008
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.APPET.2015.10.015
Abstract: The Yale Food Addiction Scale (YFAS) is a widely used tool to assess the behavioural indicators of addictive-like eating. No studies, however, have used a longitudinal design to determine whether these addictive-like eating behaviours are a stable or transient phenomenon in a community-based population. This study aimed to evaluate whether food addiction Diagnosis and Symptom scores as assessed by the YFAS remain stable over 18-months in a non-clinical population. Young adults aged 18-35 years were recruited from the community to a web-based survey in 2013. The survey included demographics, anthropometrics and the YFAS. Participants who volunteered to be recontacted for future research were invited to complete the same survey 18-months later. The YFAS scoring outputs Diagnosis and Symptom scores were tested for agreement and reliability between the two time points. Of the 303 participants who completed the original survey and agreed to be recontacted, 69 participants (22.8% of those recontacted, 94% female, 67% normal weight at baseline) completed the 18-month follow-up survey. At baseline, thirteen participants met the YFAS predefined criteria for Diagnosis, while eleven participants met these criteria at the 18-month follow-up. YFAS Diagnosis was found to have moderate agreement [K = .50, 95% CI (.23, .77)] between the two time points while Symptom scores had good agreement [K = .70, 95% CI (.54, .83)]. Intraclass correlation coefficients were interpreted as moderate over the 18-month period for both the Diagnosis [ICC = .71, 95% CI (.45, .88)] and Symptom scores [ICC = .72, 95% CI (.58, .82)]. YFAS assessed food addiction Diagnosis and Symptom scores were found to be relatively stable over 18-months in a non-clinical population of predominantly female, young adults. Future research is required to determine the impact of behavioural weight loss interventions on YFAS assessed addictive-like eating.
Publisher: Elsevier BV
Date: 2018
Publisher: Springer Science and Business Media LLC
Date: 17-09-2008
DOI: 10.1007/S10334-008-0136-0
Abstract: Proton magnetic resonance spectroscopy (MRS) is used to compare the chemistry of the transition, central and peripheral zones of the prostate. The assignments are made using two-dimensional correlated spectroscopy and the results compared with histopathology. The chemistry associated with benign prostatic hyperplasia (BPH), prostate intraepithelial neoplasia (PIN) and malignant biopsy tissues are described. There are distinct MR spectral patterns for glandular and stromal BPH, PIN and adenocarcinoma. Importantly, there are also different spectral patterns from BPH in the transitional and central zones when compared to BPH in the peripheral zone. A pattern recognition method is used to analyze the MR spectra from the biopsy specimens. The resultant mathematical classifiers generated a high level of accuracy (sensitivity and specificity of 100 and 97%). It was found that for this accuracy to be achieved, the classifiers need to be developed by comparing the spectra with specialist serial sectioned histopathology. With serial sectioned pathology the pattern recognition method was capable of identifying less than 5% of adenocarcinoma in a given piece of tissue. Many of the chemicals identified in the biopsy specimens are available for inspection from the prostate, in vivo, at 3 T.
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.MSKSP.2019.102050
Abstract: Neck muscle compositional changes may represent potential biomarkers contributing towards chronic neck-related pain and disability. To determine differences in muscle volume in the cervical muscles of in iduals with chronic idiopathic neck pain compared with age- and sex-matched asymptomatic in iduals, and to determine if these muscle variables relate to spinal level, side (left or right), age, sex, body mass index (BMI) or muscle strength. Cross-sectional magnetic resonance imaging (MRI) study. Muscle volume of five muscle (groups) from cervical levels C3-T1 in 20 pain and 17 asymptomatic participants were quantified using MRI: levator scapulae, multifidus including semispinalis cervicis, semispinalis, splenius capitus including splenius cervicis, and sternocleidomastoid. Isometric extensor and flexor muscle strength were assessed with a dynamometer. Linear mixed modelling determined differences between groups in muscle volume accounting for participant characteristics. In iduals with pain had greater muscle volume (adjusted mean difference 71.2 mm Between-group differences in cervical flexor muscle volume, and volume differences across spinal levels and muscles suggest the contribution of cervical muscles to chronic idiopathic neck pain is multifaceted and complex.
Publisher: Springer Science and Business Media LLC
Date: 02-01-2019
DOI: 10.1007/S00586-018-05868-0
Abstract: Lateral atlantoaxial (LAA) joint meniscoid composition may have clinical significance in patients following neck trauma. However, the existing method of radiologically assessing meniscoid composition has an inherent element of subjectivity, which could contribute to measurement variability. The present study sought to investigate the accuracy of two-point Dixon fat/water separation MRI as a quantitative assessment of LAA joint meniscoid composition. Sixteen LAA joint meniscoids were excised from four cadavers (mean [SD] age 79.5 [3.7] years one female) following cervical spine MRI (two-point Dixon, T1-weighted VIBE and T2-weighted SPACE sequences). Composition of LAA joint meniscoids was undertaken by (1) histological examination by light microscopy, (2) calculation of fat fraction by Dixon MRI (both in-phase/opposed-phase and fat/water methods), and (3) the existing method of considering VIBE and SPACE signal intensities. Analysis was performed using the kappa statistic with linear weighting. Microscopy revealed three, five, and eight meniscoids to be composed of adipose, fibroadipose, and fibrous tissues, respectively. Dixon sequence MRI classified 11 of these meniscoids correctly, with 'substantial' level of agreement (In-phase/Opp-phase kappa statistic = 0.78 [95% CI 0.38, 1.17] fat/water kappa statistic = 0.72 [95% CI 0.32, 1.11]). Level of agreement between microscopy and the VIBE and SPACE method was 'slight' (kappa statistic = 0.02 [95% CI - 0.34, 0.38]). Findings suggest that Dixon fat/water separation MRI may have superior utility in the assessment of LAA joint meniscoid composition than the existing method of considering VIBE and SPACE signal intensities. These slides can be retrieved under Electronic Supplementary Material.
Publisher: Elsevier BV
Date: 12-2015
Publisher: Oxford University Press (OUP)
Date: 11-2013
DOI: 10.2522/PTJ.20120477
Abstract: Manual therapy of the cervical spine has occasionally been associated with serious adverse events involving compromise of the craniocervical arteries. Ultrasound studies have shown certain neck positions can alter craniocervical arterial blood flow velocities however, findings are conflicting. Knowledge about the effects of neck position on blood flow may assist clinicians in avoiding potentially hazardous practices. The purpose of this study was to examine the effects of selected manual therapeutic interventions on blood flow in the craniocervical arteries and blood supply to the brain using magnetic resonance angiography (MRA). This was an experimental, observational magnetic resonance imaging study. Twenty adult participants who were healthy and had a mean age of 33 years were imaged using MRA in the following neck positions: neutral, rotation, rotation/distraction (similar to a Cyriax manipulation), C1–C2 rotation (similar to a Maitland or osteopathic manipulation), and distraction. The participants were imaged using 3T MRA. All participants had normal vascular anatomy. Average inflow to the brain in neutral was 6.98 mL/s and was not significantly changed by any of the test positions. There was no significant difference in flow in any of the 4 arteries in any position from neutral, despite large in idual variations. Only in iduals who were asymptomatic were investigated, and a short section of the arteries only were imaged. Blood flow to the brain does not appear to be compromised by positions commonly used in manual therapy. Positions using end-range neck rotation and distraction do not appear to be more hazardous to cerebral circulation than more segmentally localized techniques.
Publisher: Springer Science and Business Media LLC
Date: 14-03-2019
Publisher: Elsevier BV
Date: 09-2012
Publisher: Wiley
Date: 19-11-2020
DOI: 10.1111/CEO.13673
Abstract: There is limited literature on the use of optical coherence tomography in the assessment of retinal nerve fibre layer (RNFL) thickness in sports-related repetitive mild traumatic brain injury. To evaluate RNFL thickness in professional rugby league players. RNFL thinning may serve as a proxy for wider white matter degeneration. Cross-sectional observational study. Thirteen retired Australian professional rugby league players were recruited. Participants underwent binocular optical coherence tomography to measure RNFL thickness. Each participant underwent a complete ophthalmic assessment to exclude concurrent disease. RNFL thickness of each eye were compared with a normative database. Participants had played professional Rugby League for 18 years on average and reported sustaining 15 sports-related concussions throughout their career. The RNFL in participants was four micrometres thinner than that of matched normative data. Cohort average RNFL thickness was reduced in 12 out of 14 optical coherence testing parameters. These findings were statistically significant in the left inferonasal [P = .013] and left nasal [P = .006] sectors. There was no statistically significant relationship between RNFL thickness and other visual measures. This study is the first to demonstrate RNFL thinning in a cohort of retired Australian professional Rugby League players. RNFL changes have been shown to correlate with cerebral white matter loss and neurodegeneration. Optical coherence tomography may serve as a safe and economical means of screening for repetitive traumatic brain injury related neurodegeneration in contact sport athletes.
Publisher: Informa UK Limited
Date: 02-2022
DOI: 10.2147/JPR.S345365
Publisher: Research Square Platform LLC
Date: 19-05-2022
DOI: 10.21203/RS.3.RS-1634066/V1
Abstract: Muscle composition (muscle volume and muscle fat infiltrate [MFI]) may provide insight into possible mechanisms underpinning chronic idiopathic neck pain, a common condition with no definitive underlying pathology. In in iduals with chronic idiopathic neck pain 3 months and age- and sex-matched asymptomatic controls, muscle volumes of levator scapulae, multifidus (including semispinalis cervicis), semispinalis, splenius capitis (including splenius cervicis), sternocleidomastoid and longus colli from C3 through T1 were quantified from magnetic resonance imaging, with between-group differences determined using linear mixed models, accounting for side (left or right), muscle, spinal level, sex, age, and body mass index (BMI). In iduals with pain had greater muscle volume (mean difference 76.8mm 3 95% CI 26.6–127.0 p = .003) and MFI (2.3% 0.2–4.5 p = .034) of the multifidus compared to matched controls with no differences in relative volume, accounting for factors associated with the outcomes: muscle, spinal level, side (left had smaller volume, relative volume and MFI than right), sex (females had less volume and relative volume than males, age (older age associated with less relative volume and greater MFI), and BMI (higher BMI associated with greater muscle volume and MFI). Greater MFI in in iduals with chronic idiopathic neck pain suggests a possible underlying mechanism contributing to neck pain. Perspective: These findings suggest MFI in the multifidus may be radiologic sign, potentially identifying patients with a less favourable prognosis. Future studies are needed to determine if MFI is a contributor to the development or persistence of neck pain, or consequence of neck pain.
Publisher: Springer Science and Business Media LLC
Date: 05-12-2016
DOI: 10.1038/SREP38525
Abstract: Delay in cortical vein filling during the late-venous phase (delayed-LCVF) is characterized by opacification of cerebral veins despite contrast clearance from contralateral veins on dynamic computed tomography angiography (dCTA) in acute ischemic stroke (AIS) patients. The aim of the study was to investigate the associations of delayed-LCVF with clot location, reperfusion status at 24 hours, and 90-days functional outcome in AIS patients who received reperfusion therapy. A prospective cohort of AIS patients treated with intravenous thrombolysis was studied. Groupwise comparison, univariate, and multivariate regression analyses were used to study the association of delayed-LCVF with clot location and clinical outcomes. Of 93 patients (mean age = 72 ± 12 years) with hemispheric AIS included in the study, 46 (49%) demonstrated delayed-LCVF. Patients with delayed-LCVF demonstrated a significantly higher proportion of proximal occlusion (72% vs 13%, P = 0.0001), and poor reperfusion at 24 hours (41% vs 11%, P = 0.001). The proportion of poor functional outcome at 90 days was not significantly different (22/56 (48%) vs 17/61 (36%), P = 0.297). The appearance of delayed-LCVF on baseline dCTA may be a surrogate for large vessel occlusion, and an early marker for poor 24-hour angiographic reperfusion.
Publisher: Elsevier BV
Date: 12-2014
Publisher: Springer International Publishing
Date: 14-08-2020
Publisher: Radiological Society of North America (RSNA)
Date: 10-2007
Abstract: In vivo proton magnetic resonance (MR) spectroscopy (hydrogen 1 spectroscopy) provides useful information about the pathology of breast lesions by the measurement of diagnostic chemicals visible on the MR timescale. Spectroscopic measurements may be obtained following contrast-enhanced MR imaging by applying a point-resolved spatially localized spectroscopy sequence. The observation of resonances at discrete spectral frequencies allows an accurate diagnosis. In spectra obtained in vivo in malignant breast cancers, an observed resonance at 3.23 ppm is consistent with phosphocholine. In spectra from benign breast lesions and some normal breast tissue in lactating mothers and in some nonlactating healthy women, a recorded resonance at 3.28 ppm is thought to originate from glycerophosphocholine, taurine, or myoinositol. The success of in vivo spectroscopy depends on the appropriate pre-acquisition setup, acquisition protocol, and postprocessing techniques for achieving high spectral resolution and a signal-to-noise ratio sufficient to separate the resonances of the important biomarkers. When implemented correctly, the method is diagnostically accurate and robust.
Publisher: SAGE Publications
Date: 10-2014
Abstract: The aim of acute stroke treatment is to reperfuse the penumbra. However, not all posttreatment reperfusion is associated with a good outcome. Recent arterial spin labeling (ASL) studies suggest that patients with hyperperfusion after treatment have a better clinical recovery. This study aimed to determine whether there was a distinctive magnetic resonance spectroscopy (MRS) metabolite profile in hyperperfused tissue after stroke reperfusion therapy. We studied 77 ischemic stroke patients 24 hours after treatment using MRS (single voxel spectroscopy, point resolved spectroscopy, echo time 30 ms), ASL, and diffusion-weighted imaging (DWI). Magnetic resonance spectroscopy voxels were placed in cortical tissue that was penumbral on baseline perfusion imaging but had reperfused at 24 hours (and did not progress to infarction). Additionally, 20 healthy age matched controls underwent MRS. In all, 24 patients had hyperperfusion 36 had reperfused penumbra without hyperperfusion, and 17 were excluded due to no reperfusion. Hyperperfusion was significantly related to better 3-month clinical outcome compared with patients without hyperperfusion ( P = 0.007). Patients with hyperperfusion showed increased glutamate ( P .001), increased N-Acetylaspartate (NAA) ( P = 0.038), and increased lactate ( P .002) in reperfused tissue compared with contralateral tissue and healthy controls. Hyperperfused tissue has a characteristic metabolite signature, suggesting that it is more metabolically active and perhaps more capable of later neuroplasticity.
Publisher: Mary Ann Liebert Inc
Date: 2019
Abstract: Sports-related concussion is associated with a range of short-term functional deficits that are commonly thought to recover within a two-week post-injury period for most, but certainly not all, persons. Resting state electroencephalography (rs-EEG) may prove to be an affordable, accessible, and sensitive method of assessing severity of brain injury and rate of recovery after a concussion. This article presents a systematic review of rs-EEG in sports-related concussion. A systematic review of articles published in the English language, up to June 2017, was retrieved via PsychINFO, Medline, Medline In Process, Embase, SportDiscus, CINAHL, and Cochrane Library, Reviews, and Trials. The following key words were used for database searches: electroencephalography, quantitative electroencephalography, qEEG, cranio-cerebral trauma, mild traumatic brain injury, mTBI, traumatic brain injury, brain concussion, concussion, brain damage, sport, athletic, and athlete. Observational, cohort, correlational, cross-sectional, and longitudinal studies were all included in the current review. Sixteen articles met inclusion criteria, which included data on 504 athletes and 367 controls. All 16 articles reported some abnormality in rs-EEG activity after a concussion however, the cortical rhythms that were affected varied. Despite substantial methodological and analytical differences across the 16 studies, the current review suggests that rs-EEG may provide a reliable technique to identify persistent functional changes in athletes after a concussion. Because of the varied approaches, however, considerable work is needed to establish a systematic methodology to assess its efficacy as a marker of return-to-play.
Publisher: Radiological Society of North America (RSNA)
Date: 05-2011
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2005
DOI: 10.2106/JBJS.D.02923
Publisher: Wiley
Date: 22-08-2013
DOI: 10.1111/J.1552-6569.2012.00728.X
Abstract: Arterial spin labeling (ASL) is a relatively new MR perfusion technique that requires validation. One hundred patients with an acute hemispheric ischemic stroke were imaged within 6 hours of symptom onset with perfusion CT (CTP), and at 24 hours with MRI perfusion imaging, including ASL and bolus dynamic susceptibility contrast (DSC) imaging. Baseline CTP was used to define tissue at risk. This was used to determine persistent hypoperfusion, or hyperperfusion, on 24-hour ASL maps. Using 24 hour ASL, 48 of 100 patients showed hyperperfusion, and 41 showed persistent hypoperfusion. None of the PWI maps identified hyperperfusion. Compared to patients with persistent hypoperfusion on ASL, patients with hyperperfusion had less progression of acute CTP mismatch tissue to infarction at 24 hours (P = .05). ASL hyperperfusion was also associated with improved early clinical improvement: mean reduction in acute to 24 hour National Institutes of Health Stroke Scale = 12 versus 4 for ASL hypoperfusion group (P = .05), as well as 90 day modified Rankin Score (mean 2 vs. 4 for hypoperfusion group, P = .01). Hyperperfusion of the initially ischemic area identified on ASL at 24 hours poststroke identifies patients with better tissue and clinical outcomes.
Publisher: Springer Science and Business Media LLC
Date: 03-09-2005
DOI: 10.1007/S00330-004-2475-1
Abstract: The purpose was to determine if in vivo proton magnetic resonance spectroscopy ((1)H MRS) at 1.5 T can accurately provide the correct pathology of breast disease. Forty-three asymptomatic volunteers including three lactating mothers were examined and compared with 21 breast cancer patients. Examinations were undertaken at 1.5 T using a purpose-built transmit-receive single breast coil. Single voxel spectroscopy was undertaken using echo times of 135 and 350 ms. The broad composite resonance at 3.2 ppm, which includes contributions from choline, phosphocholine (PC), glycerophosphocholine (GPC), myo-inositol and taurine, was found not to be a unique marker for malignancy providing a diagnostic sensitivity and specificity of 80.0 and 86.0%, respectively. This was due to three of the asymptomatic volunteers and all of the lactating mothers also generating the broad composite resonance at 3.2 ppm. Optimised post-acquisitional processing of the spectra resolved a resonance at 3.22 ppm, consistent with PC, in patients with cancer. In contrast the spectra recorded for three false-positive volunteers, and the three lactating mothers had a resonance centred at 3.28 ppm (possibly taurine, myo-inositol or GPC). This improved the specificity of the test to 100%. Careful referencing of the spectra and post-acquisitional processing intended to optimise spectral resolution of in vivo MR proton spectra from human breast tissue resolves the composite choline resonance. This allows the distinction of patients with malignant disease from volunteers with a sensitivity of 80% and specificity of 100%. Therefore, resolution of the composite choline resonance into its constituent components improves the specificity of the in vivo (1)H MRS method, but does not overcome the problem of 20% false-negatives.
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.APPET.2018.10.009
Abstract: The concept of "food addiction" (FA) has gained popularity in view of clinical and neurobiological overlaps between excessive food intake and addictive disorders. However, no studies have examined the link between FA and striatocortical circuits involved in addictive disorders, or the influence of homeostatic status, which regulates the drive to eat, on these systems. This study aims to investigate changes in striatal functional connectivity between fasted and fed conditions among adults ranging in body mass index (BMI) and FA symptoms. Thirty adults were recruited from the general community and completed self-reported surveys including demographics, FA symptoms using the Yale Food Addiction Scale, as well as height and weight measures, used to determine BMI. Participants completed two 3-T MRI scans, one in a fasted state and one in a fed state. We conducted seed-based analyses to examine between-session ("fasted > fed") change in resting-state functional connectivity of the ventral and dorsal striatum, and its association with FA scores (controlling for BMI). Higher symptoms of FA correlated with greater changes in ventral caudate-hippoc us connectivity between fasted and fed conditions. FA symptoms did not correlate with connectivity in the dorsal caudate circuit. Post-hoc analyses revealed that participants with higher symptoms of FA had ventral caudate-hippoc us hyperconnectivity in the fasted scan only, as well as a significant reduction of this connectivity between the fasted and fed scans. Heightened connectivity in the ventral striatum during a fasted state, which has been linked to reward prediction signals, underpins symptoms of FA. In contrast, connectivity in the dorsal striatum or "habit" system is unrelated to homeostatic status and FA symptoms, and is thus less relevant for subclinical manifestations of FA.
Publisher: Springer Science and Business Media LLC
Date: 21-11-2014
DOI: 10.1007/S13246-014-0311-8
Abstract: Routine quality assurance (QA) is necessary and essential to ensure MR scanner performance. This includes geometric distortion, slice positioning and thickness accuracy, high contrast spatial resolution, intensity uniformity, ghosting artefact and low contrast object detectability. However, this manual process can be very time consuming. This paper describes the development and validation of an open source tool to automate the MR QA process, which aims to increase physicist efficiency, and improve the consistency of QA results by reducing human error. The OSAQA software was developed in Matlab and the source code is available for download from saqa-project/. During program execution QA results are logged for immediate review and are also exported to a spreadsheet for long-term machine performance reporting. For the automatic contrast QA test, a user specific contrast evaluation was designed to improve accuracy for in iduals on different display monitors. American College of Radiology QA images were acquired over a period of 2 months to compare manual QA and the results from the proposed OSAQA software. OSAQA was found to significantly reduce the QA time from approximately 45 to 2 min. Both the manual and OSAQA results were found to agree with regard to the recommended criteria and the differences were insignificant compared to the criteria. The intensity homogeneity filter is necessary to obtain an image with acceptable quality and at the same time keeps the high contrast spatial resolution within the recommended criterion. The OSAQA tool has been validated on scanners with different field strengths and manufacturers. A number of suggestions have been made to improve both the phantom design and QA protocol in the future.
Publisher: Springer Science and Business Media LLC
Date: 28-06-2016
DOI: 10.1038/SREP28713
Abstract: Repeated mild traumatic brain injuries (mTBI) may lead to serious neurological consequences, especially if re-injury occurs within the period of increased cerebral vulnerability (ICV) triggered by the initial insult. MRI and blood proteomics might provide objective measures of pathophysiological changes in mTBI and indicate when the brain is no longer in a state of ICV. This study assessed behavioral, MRI and blood-based markers in a rat model of mTBI. Rats were given a sham or mild fluid percussion injury (mFPI) and behavioral testing, MRI and blood collections were conducted up to 30 days post-injury. There were cognitive impairments for three days post-mFPI, before normalizing by day 5 post-injury. In contrast, advanced MRI (i.e., tractography) and blood proteomics (i.e., vascular endothelial growth factor) detected a number of abnormalities, some of which were still present 30 days post-mFPI. These findings suggest that MRI and blood proteomics are sensitive measures of the molecular and subtle structural changes following mTBI. Of particular significance, this study identified novel tractography measures that are able to detect mTBI and may be more sensitive than traditional diffusion-tensor measures. Furthermore, the blood and MRI findings may have important implications in understanding ICV and are translatable to the clinical setting.
Publisher: American Chemical Society (ACS)
Date: 13-04-2010
DOI: 10.1021/CR900250Y
Publisher: Mary Ann Liebert Inc
Date: 15-04-2021
Abstract: The topic of potential long-term neurological consequences from having multiple concussions during a career in collision sports is controversial. We sought to investigate white matter microstructure using diffusion tensor imaging (DTI) in retired professional Australian National Rugby League (NRL) players (
Publisher: Elsevier BV
Date: 11-2010
DOI: 10.1016/J.NEUROIMAGE.2010.06.051
Abstract: Spinal cord injury (SCI) can be accompanied by chronic pain, the mechanisms for which are poorly understood. Here we report that magnetic resonance spectroscopy measurements from the brain, collected at 3T, and processed using wavelet-based feature extraction and classification algorithms, can identify biochemical changes that distinguish control subjects from subjects with SCI as well as sub iding the SCI group into those with and without chronic pain. The results from control subjects (n=10) were compared to those with SCI (n=10). The SCI cohort was made up of subjects with chronic neuropathic pain (n=5) and those without chronic pain (n=5). The wavelet-based decomposition of frequency domain MRS signals employs statistical significance testing to identify features best suited to discriminate different classes. Moreover, the features benefit from careful attention to the post-processing of the spectroscopy data prior to the comparison of the three cohorts. The spectroscopy data, from the thalamus, best distinguished control subjects without SCI from those with SCI with a sensitivity and specificity of 0.9 (Percentage of Correct Classification). The spectroscopy data obtained from the prefrontal cortex and anterior cingulate cortex both distinguished between SCI subjects with chronic neuropathic pain and those without pain with a sensitivity and specificity of 1.0. In this study, where two underlying mechanisms co-exist (i.e. SCI and pain), the thalamic changes appear to be linked more strongly to SCI, while the anterior cingulate cortex and prefrontal cortex changes appear to be specifically linked to the presence of pain.
Publisher: MDPI AG
Date: 16-11-2021
DOI: 10.3390/NEUROLINT13040060
Abstract: Background: The interplay between collateral status and stroke aetiology may be crucial in the evaluation and management of acute ischemic stroke (AIS). Our understanding of this relationship and its level of association remains sub-optimal. This study sought to examine the association of pre-intervention collateral status with stroke aetiology, specifically large artery atherosclerosis (LAA) and cardio-embolism (CE), in AIS patients receiving reperfusion therapy, by performing a meta-analysis. Methods: Relevant search terms were explored on Medline/PubMed, Embase and Cochrane databases. Studies were included using the following inclusion criteria: (a) patients aged 18 or above (b) AIS patients (c) patients receiving reperfusion therapy (d) total cohort size of , and (e) qualitative or quantitative assessment of pre-intervention collateral status on imaging using a grading scale. Random-effects meta-analysis was performed to investigate the association of aetiology with pre-intervention collateral status, and forest plots of risk ratio (RR) were generated. Results: A meta-analysis was conducted on seven studies, with a cumulative cohort of 1235 patients, to assess the association of pre-intervention collateral status with stroke aetiology. Patients with LAA were associated significantly with an increased rate of good collaterals (RR 1.24 95% CI 1.04–1.50 p = 0.020, z = 2.33). Contrarily, CE aetiology was associated significantly with a decreased rate of good collaterals (RR 0.83 95% CI 0.71–0.98 p = 0.027, z = −2.213). Conclusions: This study demonstrates that, in AIS patients receiving reperfusion therapy, LAA and CE aetiologies are associated significantly with collateral status.
Publisher: Frontiers Media SA
Date: 09-07-2014
Publisher: Informa UK Limited
Date: 17-06-2015
DOI: 10.3109/02699052.2015.1034179
Abstract: To conduct the first video analysis of concussion in the Australian National Rugby League (NRL) and describe player and injury characteristics, situational factors and time to return to play. Descriptive, observational case series. Video analysis of 20 medically diagnosed concussions for three consenting clubs during the 2013 NRL season. Most concussions (83%) occurred during a high tackle, and all injured ball carriers were hit high. Loss of consciousness was observed in 30% of cases. Common observable signs of injury included clutching of the head, balance problems or wobbly legs and a blank or vacant state. There were no post-concussive seizures. All players with loss of consciousness were removed from play. However, only half of the total s le was removed from play and one athlete who was removed returned to play in the same match. Of the players who were removed from play, the large majority returned the following week. Illegal play accounted for 25% of all concussions. Video analysis may be a useful method to study the incidence, mechanism and management of concussion in sports such as Rugby League. Future studies may include larger numbers to validate this preliminary data and may also investigate other levels of play and age ranges.
Publisher: Mary Ann Liebert Inc
Date: 03-2018
Abstract: This study used oculomotor, cognitive, and multi-modal magnetic resonance imaging (MRI) measures to assess for neurological abnormalities in current asymptomatic amateur Australian rules footballers (i.e., Australia's most participated collision sport) with a history of sports-related concussion (SRC). Participants were 15 male amateur Australian rules football players with a history of SRC greater than 6 months previously, and 15 sex-, age-, and education-matched athlete control subjects that had no history of neurotrauma or participation in collision sports. Participants completed a clinical interview, neuropsychological measures, and oculomotor measures of cognitive control. MRI investigation involved structural imaging, as well as diffusion tensor imaging and resting-state functional MRI sequences. Despite no group differences on conventional neuropsychological tests and multi-modal MRI measures, Australian rules football players with a history of SRC performed significantly worse on an oculomotor switch task: a measure of cognitive control that interleaves the response of looking towards a target (i.e., a prosaccade) with the response of looking away from a target (i.e., an antisaccade). Specifically, Australian footballers performed significantly shorter latency prosaccades and found changing from an antisaccade trial to a prosaccade trial (switch cost) significantly more difficult than control subjects. Poorer switch cost was related to poorer performance on a number of neuropsychological measures of inhibitory control. Further, when comparing performance on the cognitively more demanding switch task with performance on simpler, antisaccade rosaccades tasks which require a single response, Australian footballers demonstrated a susceptibility to increased cognitive load, compared to the control group who were unaffected. These initial results suggest that current asymptomatic amateur Australian rules football players with a history of SRC may have persisting, subtle, cognitive changes, which are demonstrable on oculomotor cognitive measures. Future studies are required in order to further elucidate the full nature and clinical relevance of these findings.
Publisher: Springer Science and Business Media LLC
Date: 20-08-2014
DOI: 10.1007/S40279-014-0233-3
Abstract: Rugby Union, a popular full-contact sport played throughout the world, has one of the highest rates of concussion of all full-contact sports. The aim of the current review was to systematically evaluate the available evidence on concussion in Rugby Union and to conduct a meta-analysis of findings regarding the incidence of concussion. Articles were retrieved via a number of online databases. The current review examined all articles published in English up to May 2014 pertaining to concussion in Rugby Union players. The key search terms included 'Rugby Union', 'rugby', 'union', and 'football', in combination with the injury terms 'athletic injuries', 'concussion', 'sports concussion', 'sports-related concussion', 'brain concussion', 'brain injury', 'brain injuries', 'mild traumatic brain injury', 'mTBI', 'traumatic brain injury', 'TBI', 'craniocerebral trauma', 'head injury', and 'brain damage'. The final search outcome following the eligibility screening process resulted in the inclusion of 96 articles for this review. The meta-analysis included a total of 37 studies. The results of the meta-analysis revealed an overall incidence of match-play concussion in men's rugby-15s of 4.73 per 1,000 player match hours. The incidence of concussion during training was 0.07 per 1,000 practice hours. The incidence of concussion in women's rugby-15s was 0.55 per 1,000 player match hours. In men's rugby-7s match-play, concussion incidence was 3.01 per 1,000 player match hours. The incidence of concussion varied considerably between levels of play, with elite level play recording a rate of 0.40 concussions per 1,000 player match hours, schoolboy level 0.62 concussions per 1,000 player match hours, and the community or sub-elite level recording a rate of 2.08 concussions per 1,000 player match hours. The incidence of concussion in men's rugby-15s as a function of playing position (forwards vs. backs) was 4.02 and 4.85 concussions per 1,000 player match hours, respectively. Concussion is a common injury sustained and reported in match play and to a lesser extent during practice by Rugby Union players. Based on the available published data, there appears to be a variation in risk of concussion across level of play, with the sub-elite level having the greatest incidence of injury. Future research focused on studying the acute consequences and best management strategies in current players, and the potential longer term outcomes of concussion in retired players, is needed. A focus on the areas of prevention, injury identification, and medical management, and risk for long-term outcomes will be of benefit to current athletes.
Publisher: Springer Vienna
Date: 2006
DOI: 10.1007/978-3-211-35205-2_9
Abstract: Subthalamic nucleus (STN) deep brain stimulation (DBS) has become an established treatment strategy for patients with medically refractory Parkinson's disease (PD). There are however numerous strategies employed for STN lead placement. Variations include method of STN localisation, use of microelectrode recording, number of microelectrode recording passes and time taken for the procedure. We describe a relatively simple and rapid technique of STN lead placement utilising CT/ MRI image fusion, microelectrode recording and test stimulation. The first 58 consecutive patients undergoing STN DBS were assessed pre- and post-operatively. UPDRS scores, medication use and any surgical complication were assessed. Bilateral STN DBS was an efficacious treatment option for medically refractory PD. We have described a technique which can be performed with effect and low morbidity, and in a time which is well tolerated by patients.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2014
DOI: 10.1161/STROKEAHA.113.003218
Abstract: Arterial spin labeling (ASL) is a perfusion magnetic resonance imaging (MRI) technique that does not require contrast administration and thus may be more practical in hyperacute stroke than susceptibility-weighted bolus-tracking perfusion-weighted imaging (PWI). However, a threshold for ASL measurement of the ischemic penumbra needs to be determined. A total of 58 patients with acute hemispheric ischemic stroke were imaged within 6 hours of symptom onset with MRI including ASL, diffusion-weighted MRI (DWI), and PWI, after perfusion computed tomography (CTP). Patients had repeat MRI at 24 hours. On repeat imaging, 32 patients did not reperfuse and were used to determine the penumbra threshold. A receiver-operating curve and a volumetric analysis were undertaken to identify the ASL-cerebral blood flow (CBF) threshold for the acute penumbra compared with the 24-hour DWI lesion in patients without reperfusion and with the acute PWI and CTP-Tmax thresholds. An ASL-CBF threshold of 40% showed the highest area under the curve (AUC) for detection of the acute penumbra, defined by 24-hour DWI in nonreperfused patients (AUC 0.76, 95% confidence interval, 0.63–0.85), and was also accurate compared with the acute PWI-Tmax+6 seconds penumbral threshold (AUC 0.79, 95% confidence interval, 73–84) and acute CTP-Tmax 5.5 seconds penumbral threshold (AUC 0.77, 95% confidence interval, 72–84). Using a perfusion-to-diffusion mismatch ratio of 1.8:1, an ASL-CBF 40% mismatch compared with PWI-Tmax+ 6 seconds-DWI and CTP mismatch showed good sensitivity (0.81) and specificity (0.71). ASL-DWI mismatch shows potential to identify salvageable tissue in hyperacute stroke.
Publisher: Springer Science and Business Media LLC
Date: 16-09-2021
DOI: 10.1186/S40798-021-00353-3
Abstract: Rugby league is a high-intensity collision sport that carries a risk of concussion. Youth athletes are considered to be more vulnerable and take longer to recover from concussion than adult athletes. To review head impact events in elite-level junior representative rugby league and to verify and describe characteristics of X-patch TM -recorded impacts via video analysis. Observational case series. The X-patch TM was used on twenty-one adolescent players (thirteen forwards and eight backs) during a 2017 junior representative rugby league competition. Game-day footage, recorded by a trained videographer from a single camera, was synchronised with X-patch TM -recorded timest ed events. Impacts were double verified by video review. Impact rates, playing characteristics, and gameplay situations were described. The X-patch TM -recorded 624 impacts ≥ 20g between game start and finish, of which 564 (90.4%) were verified on video. Upon video review, 413 (73.2%) of all verified impacts ≥ 20g where determined to be direct head impacts. Direct head impacts ≥ 20g occurred at a rate of 5.2 impacts per game hour 7.6 for forwards and 3.0 for backs (range = 0–18.2). A defender’s arm directly impacting the head of the ball carrier was the most common event, accounting for 21.3% ( n = 120) of all impacts, and 46.7% of all “hit-up” impacts. There were no medically diagnosed concussions during the competition. The majority (90.4%) of head impacts ≥ 20g recorded by the X-patch TM sensor were verified by video. Double verification of direct head impacts in addition to cross-verification of sensor-recorded impacts using a secondary source such as synchronised video review can be used to ensure accuracy and validation of data.
Publisher: BMJ
Date: 10-04-2014
DOI: 10.1136/BJSPORTS-2013-093102
Abstract: Concussion remains one of the inherent risks of participation in rugby league. While other injuries incurred by rugby league players have been well studied, less focus and attention has been directed towards concussion. The current review examined all articles published in English from 1900 up to June 2013 pertaining to concussion in rugby league players. Publications were retrieved via six databases using the key search terms: rugby league, league, football in combination with injury terms: athletic injuries, concussion, sports concussion, sports-related concussion, brain concussion, brain injury, brain injuries, mild traumatic brain injury, mTBI, traumatic brain injury, TBI, craniocerebral trauma, head injury and brain damage. Observational, cohort, correlational, cross-sectional and longitudinal studies were all included. 199 rugby league injury publications were identified. 39 (20%) were related in some way to concussion. Of the 39 identified articles, 6 (15%) had the main aim of evaluating concussion, while the other 33 reported on concussion incidence as part of overall injury data analyses. Rugby league concussion incidence rates vary widely from 0.0 to 40.0/1000 playing hours, depending on the definition of injury (time loss vs no time loss). The incidence rates vary across match play versus training session, seasons (winter vs summer) and playing position (forwards vs backs). The ball carrier has been found to be at greater risk for injury than tacklers. Concussion accounts for 29% of all injuries associated with illegal play, but only 9% of injuries sustained in legal play. In comparison with other collision sports, research evaluating concussion in rugby league is limited. With such limited published rugby league data, there are many aspects of concussion that require attention, and future research may be directed towards these unanswered questions.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2014
Publisher: Springer Science and Business Media LLC
Date: 14-04-2015
Publisher: American Physiological Society
Date: 10-2020
DOI: 10.1152/JAPPLPHYSIOL.00290.2020
Abstract: An emerging method to measure muscle activation patterns is muscle functional magnetic resonance imaging (mfMRI), where preexercise and postexercise muscle metabolism differences indicate spatial muscle activation patterns. We evaluated studies employing mfMRI to determine activation patterns of lumbar or lower limb muscles following exercise in physically active adults. Electronic systematic searches were conducted until March 2020. All studies employing ≥1.5 Tesla MRI scanners to compare spatial muscle activation patterns at the level of or inferior to the first lumbar vertebra in healthy, active adults. Two authors independently assessed study eligibility before appraising methodological quality using a National Institutes of Health assessment tool. Because of heterogeneity, findings were synthesized without meta-analysis. Of the 1,946 studies identified, seven qualified for inclusion and pertained to hamstring ( n = 5), quadriceps ( n = 1) or extrinsic foot ( n = 1) muscles. All included studies controlled for internal validity, with one employing assessor blinding. MRI physics and differing research questions explain study methodology heterogeneity. Significant mfMRI findings were: following Nordic exercise, hamstrings with previous trauma (strain or surgical autograft harvest) demonstrated reduced activation compared with unharmed contralateral muscles, and asymptomatic in iduals preferentially activated semitendinosus greater biceps femoris long head to semitendinosus ratios reported following 45° hip extension over Nordic exercise greater rectus femoris activation occurred in “flywheel” over barbell squats. mfMRI parameters differ on the basis of in idual research questions. In idual muscles show greater activation following specific exercises, suggesting exercise specificity may be important for rehabilitation, although evidence is limited to single cohort studies comparing interlimb differences preexercise versus postexercise.
Publisher: British Institute of Radiology
Date: 10-2014
DOI: 10.1259/BJR.20140325
Publisher: MDPI AG
Date: 23-10-2023
Publisher: IOP Publishing
Date: 24-03-2014
Publisher: Georg Thieme Verlag KG
Date: 13-02-2017
Abstract: The aim of this study was to examine brain neurometabolite concentrations in retired rugby league players who had a history of numerous self-reported concussions. Participants were 16 retired professional rugby league players (ages 30-45 years) with an extensive history of concussion and participation in contact sports, and 16 age- and education-matched controls who had no history of neurotrauma or participation in contact sports. All completed a clinical interview, psychological and cognitive testing, and magnetic resonance spectroscopy (MRS) investigation. MRS voxels were placed in posterior cingulate grey matter and parietal white matter. Neurometabolite concentrations were quantified using LCModel. It was hypothesized that retired athletes would differ on N-acetyl aspartate, myo-inositol, choline, glutamate, and glutathione. Retired players had significantly lower concentrations of grey matter glutathione (p=0.02, d=0.91). They did not significantly differ in concentrations of other neurometabolites. There were no significant differences between groups on measures of depression, anxiety, or cognitive functioning. The retired athletes reported significantly greater alcohol use (p<0.01 Cohen's d=1.49), and they had worse manual dexterity using their non-dominant hand (p=0.03 d=1.08). These preliminary findings suggest that MRS might be modestly sensitive to biochemical differences in athletes after their athletic careers have ended in the absence of clinical differences in cognitive performance and self-reported psychological functioning.
Publisher: Wiley
Date: 22-09-2014
Abstract: There is mounting evidence that the mechanical property of tissues provides important cues that control cell fate. However, implementation of hydrogels with tunable physicochemical properties is limited due to the challenges associated with crosslinking chemistries. It has been recently shown that mechanically well-defined injectable polysaccharide hydrogels can be engineered by switching their secondary structure from an α-helix to a β-sheet. Based on these findings, a new concept is presented to tailor the mechanical properties of agarose hydrogels via the blending with the β-sheet-rich carboxylated derivative. Using this simple strategy, gels with predictable roughness, fiber organization, and shear modulus ranging from 0.1 to 100 kPa can be formulated. Hydrogels whose mechanical properties can be precisely tailored in vivo without the recourse for chemical reactions are expected to play an important role in implementing mechanobiology paradigms in de novo tissue engineering.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2006
DOI: 10.1213/01.ANE.0000198333.22687.A6
Abstract: Magnetic resonance (MR) spectroscopy is a noninvasive technique that can be used to detect and measure the concentration of metabolites and neurotransmitters in the brain and other organs. We used in vivo (1)H MR spectroscopy in subjects with low back pain compared with control subjects to detect alterations in biochemistry in three brain regions associated with pain processing. A pattern recognition approach was used to determine whether it was possible to discriminate accurately subjects with low back pain from control subjects based on MR spectroscopy. MR spectra were obtained from the prefrontal cortex, anterior cingulate cortex, and thalamus of 32 subjects with low back pain and 33 control subjects without pain. Spectra were analyzed and compared between groups using a pattern recognition method (Statistical Classification Strategy). Using this approach, it was possible to discriminate between subjects with low back pain and control subjects with accuracies of 100%, 99%, and 97% using spectra obtained from the anterior cingulate cortex, thalamus, and prefrontal cortex, respectively. These results demonstrate that MR spectroscopy, in combination with an appropriate pattern recognition approach, is able to detect brain biochemical changes associated with chronic pain with a high degree of accuracy.
Publisher: Frontiers Media SA
Date: 06-04-2022
DOI: 10.3389/FNEUR.2022.817709
Abstract: A cavum septum pellucidum (CSP) has been reported as a visible brain anomaly in normal in iduals as well in some former combat and collision sport athletes. The appearance of CSP with fenestrations and ventricular enlargement are considered associated features of the neuropathological diagnosis of chronic traumatic encephalopathy. The current study examined CSP anatomic features and lateral ventricle size in retired elite rugby league players and controls. Forty-one retired rugby league players and 41 healthy community controls, similar in age and education, underwent structural MRI scans. CSP grade, CSP length, corpus callosum septal length, and Evans' ratio (for lateral ventricle size) were rated by two of the current study authors. All participants also self-reported concussion exposure histories, depressive symptoms, daytime sleepiness, and impulsivity. They completed a neuropsychological test battery assessing premorbid intellectual functioning, attention, processing speed, language, visuospatial skills, memory, and aspects of executive functioning. The two raters had high agreement for CSP grade (Cohen's κ = 0.80), CSP length [intraclass correlation (ICC) = 0.99], corpus callosum septal length (ICC = 0.73), the CSP/septal ratio (ICC = 0.99), and the Evans' ratio (ICC = 0.75). Twenty-five retired players (61.0%) had an abnormal CSP compared to 17 controls [41.5% χ ( 1 , 82 ) 2 = 3.12, p = 0.08, odds ratio = 2.21]. The CSP/septal ratio was larger for retired players than for the controls. The Evans' ratio did not differ between the two groups. In the retired rugby league players ( n = 41), those with normal ( n = 16) and abnormal ( n = 25) CSP grades did not differ across age, age of first exposure to collision sport, years of sport exposure, concussion history, or 23 clinical and cognitive variables. This study revealed a difference in the size of the CSP between retired professional rugby league players and controls. There was no significant difference in the size of the ventricles between the two groups. There were no significant differences between those with vs. without an abnormal CSP on age of first exposure to rugby league, years of exposure to repetitive neurotrauma, number of lifetime concussions, depression, impulsivity, perceived cognitive decline, or on any neuropsychological test.
No related grants have been discovered for Peter Stanwell.