ORCID Profile
0000-0001-8076-7532
Current Organisations
Lions Eye Institute
,
University of Western Australia
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Publisher: Elsevier BV
Date: 02-2009
DOI: 10.1016/J.JELEKIN.2007.02.018
Abstract: The pattern of tonic and phasic components in an EMG signal reflects the underlying behaviour of the central nervous system (CNS) in controlling the musculature. One avenue for gaining a better understanding of this behaviour is to seek a quantitative characterisation of these phasic and tonic components. We propose that these signal characteristics can range between unvarying, tonic and intermittent, phasic activation through a continuum of EMG litude modulation. In this paper, we present two new algorithms for quantifying litude modulation: a linear-envelope approach, and a mathematical morphology approach. In addition we present an algorithm for synthesising EMG signals with known litude modulation. The efficacy of the synthesis algorithm is demonstrated using real EMG data. We present an evaluation and comparison of the two algorithms for quantifying litude modulation based on synthetic data generated by the proposed synthesis algorithm. The results demonstrate that the EMG synthesis parameters represent 91.9% and 96.2% of the variance of linear-envelopes extracted from lumbo-pelvic muscle EMG signals collected from subjects performing a repetitive-movement task. This depended, however, on the muscle and movement-speed considered (F=4.02, p<0.001). Coefficients of determination between input and output litude modulation variables were used to quantify the accuracy of the linear-envelope and morphological signal processing algorithms. The linear-envelope algorithm exhibited higher coefficients of determination than the most accurate morphological approach (and hence greater accuracy, T=8.16, p<0.001). Similarly, the standard deviation of the coefficients of determination was 1.691 times smaller (p<0.001). This signal processing algorithm represents a novel tool for the quantification of litude modulation in continuous EMG signals and can be used in the study of CNS motor control of the musculature in repetitive-movement tasks.
Publisher: Institution of Engineering and Technology (IET)
Date: 06-2013
Publisher: Springer Science and Business Media LLC
Date: 1999
Publisher: IEEE
Date: 09-2009
Publisher: IEEE
Date: 07-2013
Publisher: Frontiers Media SA
Date: 26-11-2020
DOI: 10.3389/FNANA.2020.560534
Abstract: There is currently a limited understanding of the morphological and functional organization of the olfactory system in cartilaginous fishes, particularly when compared to bony fishes and terrestrial vertebrates. In this fish group, there is a clear paucity of information on the characterization, density, and distribution of olfactory receptor neurons (ORNs) within the sensory olfactory epithelium lining the paired olfactory rosettes, and their functional implications with respect to the hydrodynamics of incurrent water flow into the nares. This imaging study examines the brownbanded bamboo shark Chiloscyllium punctatum (Elasmobranchii) and combines immunohistochemical labeling using antisera raised against five G-protein α-subunits (Gα s/olf , Gα q/ 11 / 14 , Gα i– 1 / 2 / 3 , Gα i– 3 , Gα o ) with light and electron microscopy, to characterize the morphological ORN types present. Three main ORNs (“long”, “microvillous” and “crypt-like”) are confirmed and up to three additional microvilli-bearing types are also described “Kappe-like” (potential or homologous “Kappe” as in teleosts), “pear-shaped” and “teardrop-shaped” cells. These morphotypes will need to be confirmed molecularly in the future. Using X-ray diffusible iodine-based contrast-enhanced computed tomography (diceCT), high-resolution scans of the olfactory rosettes, olfactory bulbs (OBs), peduncles, and telencephalon reveal a lateral segregation of primary olfactory inputs within the OBs, with distinct medial and lateral clusters of glomeruli, suggesting a potential somatotopic organization. However, most ORN morphotypes are found to be ubiquitously distributed within the medial and lateral regions of the olfactory rosette, with at least three microvilli-bearing ORNs labeled with anti-Gα o found in significantly higher densities in lateral lamellae [in lateral lamellae] and on the anterior portion of lamellae (facing the olfactory cavity). These microvilli-bearing ORN morphotypes (microvillous, “Kappe-like,” “pear-shaped,” and “teardrop-shaped”) are the most abundant across the olfactory rosette of this species, while ciliated ORNs are less common and crypt cells are rare. Spatial simulations of the fluid dynamics of the incurrent water flow into the nares and within the olfactory cavities indicate that the high densities of microvilli-bearing ORNs located within the lateral region of the rosette are important for s ling incoming odorants during swimming and may determine subsequent tracking behavior.
Publisher: IEEE
Date: 2009
Publisher: The Royal Society
Date: 07-07-2021
Abstract: Sexually antagonistic coevolution can drive the evolution of male traits that harm females, and female resistance to those traits. While males have been found to vary their harmfulness to females in response to social cues, plasticity in female resistance traits remains to be examined. Here, we ask whether female seed beetles Callosobruchus maculatus are capable of adjusting their resistance to male harm in response to the social environment. Among seed beetles, male genital spines harm females during copulation and females might resist male harm via thickening of the reproductive tract walls. We develop a novel micro computed tomography imaging technique to quantify female reproductive tract thickness in three-dimensional space, and compared the reproductive tracts of females from populations that had evolved under high and low levels of sexual conflict, and for females reared under a social environment that predicted either high or low levels of sexual conflict. We find little evidence to suggest that females can adjust the thickness of their reproductive tracts in response to the social environment. Neither did evolutionary history affect reproductive tract thickness. Nevertheless, our novel methodology was capable of quantifying fine-scale differences in the internal reproductive tracts of in idual females, and will allow future investigations into the internal organs of insects and other animals.
Publisher: British Institute of Radiology
Date: 03-2011
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2011
Publisher: IEEE
Date: 2008
Publisher: Wiley
Date: 02-12-2013
DOI: 10.1002/JMRI.24229
Abstract: To present and evaluate a fully automatic method for segmentation (i.e., detection and delineation) of suspicious tissue in breast MRI. The method, based on mean-shift clustering and graph-cuts on a region adjacency graph, was developed and its parameters tuned using multimodal (T1, T2, DCE-MRI) clinical breast MRI data from 35 subjects (training data). It was then tested using two data sets. Test set 1 comprises data for 85 subjects (93 lesions) acquired using the same protocol and scanner system used to acquire the training data. Test set 2 comprises data for eight subjects (nine lesions) acquired using a similar protocol but a different vendor's scanner system. Each lesion was manually delineated in three-dimensions by an experienced breast radiographer to establish segmentation ground truth. The regions of interest identified by the method were compared with the ground truth and the detection and delineation accuracies quantitatively evaluated. One hundred percent of the lesions were detected with a mean of 4.5 ± 1.2 false positives per subject. This false-positive rate is nearly 50% better than previously reported for a fully automatic breast lesion detection system. The median Dice coefficient for Test set 1 was 0.76 (interquartile range, 0.17), and 0.75 (interquartile range, 0.16) for Test set 2. The results demonstrate the efficacy and accuracy of the proposed method as well as its potential for direct application across different MRI systems. It is (to the authors' knowledge) the first fully automatic method for breast lesion detection and delineation in breast MRI.
Publisher: Scientific Research Publishing, Inc.
Date: 2015
Publisher: American Geophysical Union (AGU)
Date: 12-2017
DOI: 10.1002/2017GC007278
Publisher: IEEE
Date: 08-2006
Publisher: Elsevier BV
Date: 2022
DOI: 10.1016/J.OPTOM.2022.11.001
Abstract: Retinal and optic disc images are used to assess changes in the retinal vasculature. These can be changes associated with diseases such as diabetic retinopathy and glaucoma or induced using ophthalmodynamometry to measure arterial and venous pressure. Key steps toward automating the assessment of these changes are the segmentation and classification of the veins and arteries. However, such segmentation and classification are still required to be manually labelled by experts. Such automated labelling is challenging because of the complex morphology, anatomical variations, alterations due to disease and scarcity of labelled data for algorithm development. We present a deep machine learning solution called the multiscale guided attention network for retinal artery and vein segmentation and classification (MSGANet-RAV). MSGANet-RAV was developed and tested on 383 colour clinical optic disc images from LEI-CENTRAL, constructed in-house and 40 colour fundus images from the AV-DRIVE public dataset. The datasets have a mean optic disc occupancy per image of 60.6% and 2.18%, respectively. MSGANet-RAV is a U-shaped encoder-decoder network, where the encoder extracts multiscale features, and the decoder includes a sequence of self-attention modules. The self-attention modules explore, guide and incorporate vessel-specific structural and contextual feature information to segment and classify central optic disc and retinal vessel pixels. MSGANet-RAV achieved a pixel classification accuracy of 93.15%, sensitivity of 92.19%, and specificity of 94.13% on LEI-CENTRAL, outperforming several reference models. It similarly performed highly on AV-DRIVE with an accuracy, sensitivity and specificity of 95.48%, 93.59% and 97.27%, respectively. The results show the efficacy of MSGANet-RAV for identifying central optic disc and retinal arteries and veins. The method can be used in automated systems designed to assess vascular changes in retinal and optic disc images quantitatively.
Publisher: Springer Science and Business Media LLC
Date: 15-04-0055
Publisher: No publisher found
Date: 2013
Publisher: ACM
Date: 12-11-2016
Publisher: IEEE
Date: 12-2007
Publisher: IEEE
Date: 12-2010
Publisher: IEEE
Date: 08-2006
Publisher: Hindawi Limited
Date: 2015
DOI: 10.1155/2015/138060
Abstract: The monoexponential model is widely used in quantitative biomedical imaging. Notable applications include apparent diffusion coefficient (ADC) imaging and pharmacokinetics. The application of ADC imaging to the detection of malignant tissue has in turn prompted several studies concerning optimal experiment design for monoexponential model fitting. In this paper, we propose a new experiment design method that is based on minimizing the determinant of the covariance matrix of the estimated parameters (D-optimal design). In contrast to previous methods, D-optimal design is independent of the imaged quantities. Applying this method to ADC imaging, we demonstrate its steady performance for the whole range of input variables (imaged parameters, number of measurements, and range of b -values). Using Monte Carlo simulations we show that the D-optimal design outperforms existing experiment design methods in terms of accuracy and precision of the estimated parameters.
Publisher: IEEE
Date: 12-2010
Publisher: Springer Science and Business Media LLC
Date: 23-12-2014
Publisher: Elsevier BV
Date: 03-2023
Publisher: Edinburgh University Library
Date: 11-09-2019
Abstract: The National Imaging Facility (NIF) provides Australian researchers with state-of-the-art instrumentation—including magnetic resonance imaging (MRI), positron emission tomography (PET), X-ray computed tomography (CT) and multispectral imaging – and expertise for the characterisation of animals, plants and materials. To maximise research outcomes, as well as to facilitate collaboration and sharing, it is essential not only that the data acquired using these instruments be managed, curated and archived in a trusted data repository service, but also that the data itself be of verifiable quality. In 2017, several NIF nodes collaborated on a national project to define the requirements and best practices necessary to achieve this, and to establish exemplar services for both preclinical MRI data and clinical ataxia MRI data. In this paper we describe the project, its key outcomes, challenges and lessons learned, and future developments, including extension to other characterisation facilities and instruments/modalities.
Publisher: Hindawi Limited
Date: 2015
DOI: 10.1155/2015/760230
Abstract: The design of an optimal gradient encoding scheme (GES) is a fundamental problem in diffusion MRI. It is well studied for the case of second-order tensor imaging (Gaussian diffusion). However, it has not been investigated for the wide range of non-Gaussian diffusion models. The optimal GES is the one that minimizes the variance of the estimated parameters. Such a GES can be realized by minimizing the condition number of the design matrix ( K -optimal design). In this paper, we propose a new approach to solve the K -optimal GES design problem for fourth-order tensor-based diffusion profile imaging. The problem is a nonconvex experiment design problem. Using convex relaxation, we reformulate it as a tractable semidefinite programming problem. Solving this problem leads to several theoretical properties of K -optimal design: (i) the odd moments of the K -optimal design must be zero (ii) the even moments of the K -optimal design are proportional to the total number of measurements (iii) the K -optimal design is not unique, in general and (iv) the proposed method can be used to compute the K -optimal design for an arbitrary number of measurements. Our Monte Carlo simulations support the theoretical results and show that, in comparison with existing designs, the K -optimal design leads to the minimum signal deviation.
Publisher: IEEE
Date: 08-2014
Publisher: SPIE
Date: 04-03-2010
DOI: 10.1117/12.840019
Publisher: IEEE
Date: 12-2010
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2010
Publisher: IEEE
Date: 07-2013
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 19-10-2023
Publisher: Elsevier BV
Date: 10-1997
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.CMPB.2019.104984
Abstract: Optimal development of placental vasculature is critical for fetal growth and health outcomes. Many studies characterizing the vascular structure of the fetal side of the placenta have utilized a range of two-dimensional and three-dimensional (3D) imaging techniques including X-ray micro-computed tomography (micro-CT) following perfusion of the vasculature with a radio-opaque compound. The CT approach has been used to study feto-placental vasculature in rodents and humans. Its inherent advantage is that it reveals the 3D structure in high resolution without destroying the s le. This permits both multiple scanning of the s le and follow-up histological investigations in the same s le. Nevertheless, the applicability of the approach is h ered both by the challenging segmentation of the vasculature and a lack of straightforward methodology to quantitate the feto-placental vascular network. This paper addresses these challenges. An end-to-end methodology is presented for automatically segmenting the vasculature obtaining a Strahler-ordered rooted-tree representation and extracting quantitative features from its nodes, segments and branches (including volume, length, tortuosity and branching angles). The methodology is demonstrated for rat and mouse placentas at the end of gestation (day 22 and day 18, respectively), perfused with Microfil® and imaged using two different micro-CT scanners. The 3D visualizations of the resulting vascular trees clearly demonstrate differences between the branching complexity, tree span and tree depth of the mouse and rat placentas. The quantitative characterizations of these trees include not only the fundamental features that have been utilized in other studies of feto-placental vasculature but also several additional features. Boxplots of several of these-tortuosity, number of side branches, number of offspring per branch and branch volume-computed at each Strahler order are presented and interpreted. Differences and similarities between the mouse and rat casts are readily detected. The proposed end-to-end methodology, and the implementation presented using a combination of Amira and Matlab, offers researchers in the field of placental vasculature characterization a straightforward and objective approach for quantifying micro-CT vascular datasets.
Publisher: IEEE
Date: 08-2012
Publisher: SAGE Publications
Date: 11-2007
DOI: 10.1177/154405910708601107
Abstract: The task of identifying human remains based on dental comparisons of post mortem (PM) and ante mortem (AM) radiographs is labor-intensive, subjective, and has several drawbacks, including: inherently poor image quality, difficulty matching the viewing angles in PM radiographs to those taken AM, and the fact that the state of the dental remains may entirely preclude the possibility of obtaining certain types of radiographs PM. The aim of the present study was to investigate the feasibility of using radiograph-like images reconstructed from PM x-ray computed tomography (CT) data to overcome the shortcomings of conventional radiographic comparison. Algorithms for computer synthesis of panoramic, periapical, and bitewing images are presented. The algorithms were evaluated with data from clinical examinations of two persons. The results demonstrate the efficacy of the CT-based approach and that, in comparison with conventional radiographs, the synthesized images exhibit minimal geometric distortion, reduced blurring, and reduced superimposition of oral structures.
Publisher: Springer Science and Business Media LLC
Date: 08-04-2023
DOI: 10.1186/S13104-023-06309-Y
Abstract: Using the novel imaging method of high-speed modified photoplethysmography we measured the retinal venous pulse wave velocity in a single case. A healthy 30-year-old subject underwent high-speed modified photoplethysmography (120 frames per second) with simultaneous ophthalmodynamometry at 26 Meditron units. A video of the optic nerve was analyzed using custom software. A harmonic regression model was fitted to each pixel in the time series and used to quantify the retinal vascular pulse wave parameters. Retinal venous pulsation at the optic disc was observed as a complex dynamic wall motion, whereas contraction commenced at a point in the vein at the center of the optic disc, and progressed centrifugally. The empirically estimated retinal venous pulse wave velocity at this segment was approximately 22.24694 mm/s. This measurement provides an estimate for future studies in the field.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2016
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 19-01-2021
DOI: 10.1167/TVST.10.1.29
Publisher: Springer Science and Business Media LLC
Date: 09-05-2023
DOI: 10.1038/S41598-023-33490-8
Abstract: An adequate blood supply to meet the energy demands is essential for any tissue, particularly for high energy demand tissues such as the retina. A critical question is: How is the dynamic match between neuronal demands and blood supply achieved? We present a quantitative assessment of temporal and spatial variations in perfusion in the macular capillary network in 10 healthy human subjects using a non-invasive and label-free imaging technique. The assessment is based on the calculation of the coefficient of variation (CoV) of the perfusion signal from arterioles, venules and capillaries from a sequence of optical coherence tomography angiography images centred on the fovea. Significant heterogeneity of the spatial and temporal variation was found within arterioles, venules and capillary networks. The CoV values of the capillaries and smallest vessels were significantly higher than that in the larger vessels. Our results demonstrate the presence of significant heterogeneity of spatial and temporal variation within each element of the macular microvasculature, particularly in the capillaries and finer vessels. Our findings suggest that the dynamic match between neuronal demands and blood supply is achieved by frequent alteration of local blood flow evidenced by capillary perfusion variations both spatially and temporally in the macular region.
Publisher: IEEE
Date: 08-2014
Publisher: Springer Science and Business Media LLC
Date: 31-03-2023
DOI: 10.1038/S41526-023-00269-0
Abstract: Spaceflight associated neuro-ocular syndrome (SANS) is common amongst astronauts on long duration space missions and is associated with signs consistent with elevated cerebrospinal fluid (CSF) pressure. Additionally, CSF pressure has been found to be elevated in a significant proportion of astronauts in whom lumbar puncture was performed after successful mission completion. We have developed a retinal photoplethysmographic technique to measure retinal vein pulsation litudes. This technique has enabled the development of a non-invasive CSF pressure measurement apparatus. We tested the system on healthy volunteers in the sitting and supine posture to mimic the range of tilt table extremes and estimated the induced CSF pressure change using measurements from the CSF hydrostatic indifferent point. We found a significant relationship between pulsation litude change and estimated CSF pressure change ( p 0.0001) across a range from 2.7 to 7.1 mmHg. The increase in pulse litude was highest in the sitting posture with greater estimated CSF pressure increase ( p 0.0001), in keeping with physiologically predicted CSF pressure response. This technique may be useful for non-invasive measurement of CSF pressure fluctuations during long-term space voyages.
Publisher: IEEE
Date: 06-2012
Publisher: IEEE
Date: 08-2007
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.PRETEYERES.2019.01.001
Abstract: The central role of the cardiovascular system is to maintain adequate capillary perfusion. The spatially and temporally heterogeneous nature of capillary perfusion has been reported in some organs. However, such heterogeneous perfusion properties have not been sufficiently explored in the retina. Arguably, spatial and temporal heterogeneity of capillary perfusion could be more predominant in the retina than that in other organs. This is because the retina is one of the highest metabolic demand neural tissues yet it has a limited blood supply due to optical requirements. In addition, the unique heterogeneous distribution of retinal neural cells within different layers and regions, and the significant heterogeneity of intraretinal oxygen distribution and consumption add to the complexity. Retinal blood flow distribution must match consumption of nutrients such as oxygen and glucose within the retina at the cellular level in order to effectively maintain cell survival and function. Sophisticated local blood flow control in the microcirculation is likely required to control the retinal capillary perfusion to supply local retinal tissue and accommodate temporal and spatial variations in metabolic supply and demand. The authors would like to update the knowledge of the retinal microvessel and capillary network and retinal oxidative metabolism from their own studies and the work of others. The coupling between blood supply and energy demands in the retina is particularly interesting. We will mostly describe information regarding the retinal microvessel network and retinal oxidative metabolism relevant to the spatial and temporal heterogeneity of capillary perfusion. We believe that there is significant and necessary spatial and temporal heterogeneity and active regulation of retinal blood flow in the retina, particularly in the macular region. Recently, retinal optical coherence tomography angiography (OCTA) has been widely used in ophthalmology, both experimentally and clinically. OCTA could be a valuable tool for examining retinal microvessel and capillary network structurally and has potential for determining retinal capillary perfusion and its control. We have demonstrated spatial and temporal heterogeneity of capillary perfusion in the retina both experimentally and clinically. We have also found close relationships between the smallest arterioles and capillaries within paired arterioles and venules and determined the distribution of smooth muscle cell contraction proteins in these vessels. Spatial and temporal heterogeneity of retinal capillary perfusion could be a useful parameter to determine retinal microvessel regulatory capability as an early assay for retinal vascular diseases. This topic will be of great interest, not only for the eye but also other organs. The retina could be the best model for such investigations. Unlike cerebral vessels, retinal vessels can be seen even at the capillary level. The purpose of this manuscript is to share our current understanding with the readers and encourage more researchers and clinicians to investigate this field. We begin by reviewing the general principles of microcirculation properties and the spatial and temporal heterogeneity of the capillary perfusion in other organs, before considering the special requirements of the retina. The local heterogeneity of oxygen supply and demand in the retina and the need to have a limited and well-regulated retinal circulation to preserve the transparency of the retina is discussed. We then consider how such a delicate balance of metabolic supply and consumption is achieved. Finally we discuss how new imaging methodologies such as optical coherence tomography angiography may be able to detect the presence of spatial and temporal heterogeneity of capillary perfusion in a clinical setting. We also provide some new information of the control role of very small arterioles in the modulation of retinal capillary perfusion which could be an interesting topic for further investigation.
Publisher: MDPI AG
Date: 03-04-2020
Abstract: Postnatal glucocorticoids such as dexamethasone are effective in promoting lung development in preterm infants, but are prescribed cautiously due to concerns of neurological harm. We developed an analysis pipeline for post-mortem magnetic resonance imaging (MRI) to assess brain development and hence the neurological safety profile of postnatal dexamethasone in preterm lambs. Lambs were delivered via caesarean section at 129 days’ (d) gestation (full term ≈ 150 d) with saline-vehicle control (Saline, n = 9), low-dose tapered dexamethasone (cumulative dose = 0.75 mg/kg, n = 8), or high-dose tapered dexamethasone (cumulative dose = 2.67 mg/kg, n = 8), for seven days. Naïve fetal lambs (136 d gestation) were used as end-point maturation controls. The left-brain hemispheres were immersion-fixed in 10 % formalin (24 h), followed by paraformaldehyde ( months). Image sequences were empirically optimized for T1- and T2-weighted MRI and analysed using accessible methods. Spontaneous lesions detected in the white matter of the frontal cortex, temporo-parietal cortex, occipital lobe, and deep to the parahippoc al gyrus were confirmed with histology. Neither postnatal dexamethasone treatment nor gestation showed any associations with lesion incidence, frontal cortex (total, white, or grey matter) or hippoc al volume (all p 0.05). Postnatal dexamethasone did not appear to adversely affect neurodevelopment. Our post-mortem MRI analysis pipeline is suitable for other animal models of brain development.
Publisher: Wiley
Date: 04-2009
DOI: 10.1002/CMR.B.20133
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2007
Publisher: Springer Berlin Heidelberg
Date: 2013
DOI: 10.1007/978-3-642-40811-3_86
Abstract: Several data acquisition schemes for diffusion MRI have been proposed and explored to date for the reconstruction of the 2nd order tensor. Our main contributions in this paper are: (i) the definition of a new class of s ling schemes based on repeated measurements in every s ling point (ii) two novel schemes belonging to this class and (iii) a new reconstruction framework for the second scheme. We also present an evaluation, based on Monte Carlo computer simulations, of the performances of these schemes relative to known optimal s ling schemes for both 2nd and 4th order tensors. The results demonstrate that tensor estimation by the proposed s ling schemes and estimation framework is more accurate and robust.
Publisher: Society for Neuroscience
Date: 29-05-2020
DOI: 10.1523/ENEURO.0076-20.2020
Abstract: Contrast-enhanced X-ray imaging provides a non-destructive and flexible approach to optimizing contrast in soft tissues, especially when incorporated with Lugol’s solution (aqueous I 2 KI), a technique currently referred to as diffusible iodine-based contrast-enhanced computed tomography (diceCT). This stain exhibits high rates of penetration and results in excellent contrast between and within soft tissues, including the central nervous system. Here, we present a staining method for optimizing contrast in the brain of a cartilaginous fish, the brownbanded bamboo shark, Chiloscyllium punctatum , and a bony fish, the common goldfish, Carassius auratus , using diceCT. The aim of this optimization procedure is to provide suitable contrast between neural tissue and background tissue(s) of the head, thereby facilitating digital segmentation and volumetric analysis of the central nervous system. Both species were scanned before staining and were rescanned at time (T) intervals, either every 48 h ( C. punctatum ) or every 24 h ( C. auratus ), to assess stain penetration and contrast enhancement. To compare stain intensities, raw X-ray CT data were reconstructed using air and water calibration phantoms that were scanned under identical conditions to the s les. Optimal contrast across the brain was achieved at T = 240 h for C. punctatum and T = 96 h for C. auratus . Higher resolution scans of the whole brain were obtained at the two optimized staining times for all the corresponding specimens. The use of diceCT provides a new and valuable tool for visualizing differences in the anatomic organization of both the central and peripheral nervous systems of fish.
Publisher: SPIE
Date: 29-03-2013
DOI: 10.1117/12.2007185
Start Date: 2005
End Date: 2006
Funder: Australian Research Council
View Funded ActivityStart Date: 2007
End Date: 2009
Funder: Australian Research Council
View Funded Activity