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Segmented MRI

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https://www.readbyqxmd.com/read/28334358/ranges-of-cervical-intervertebral-disc-deformation-during-an-in-vivo-dynamic-flexion-extension-of-the-neck
#1
Yan Yu, Haiqing Mao, Jing-Sheng Li, Tsung-Yuan Tsai, Liming Cheng, Kirkham B Wood, Guoan Li, Thomas D Cha
While abnormal loading is widely believed to cause cervical spine disc diseases, in-vivo cervical disc deformation during dynamic neck motion has not been well delineated. This study investigated the range of cervical disc deformation during an in-vivo functional flexion-extension of the neck. Ten asymptomatic human subjects were tested using a combined dual fluoroscopic imaging system and MRI based 3D modeling technique. Overall disc deformation was determined using the changes of the space geometry between upper and lower endplates of each intervertebral segment (C3/4, C4/5, C5/6 and C6/7)...
March 23, 2017: Journal of Biomechanical Engineering
https://www.readbyqxmd.com/read/28334314/a-template-and-probabilistic-atlas-of-the-human-sensorimotor-tracts-using-diffusion-mri
#2
Derek B Archer, David E Vaillancourt, Stephen A Coombes
The purpose of this study was to develop a high-resolution sensorimotor area tract template (SMATT) which segments corticofugal tracts based on 6 cortical regions in primary motor cortex, dorsal premotor cortex, ventral premotor cortex, supplementary motor area (SMA), pre-supplementary motor area (preSMA), and primary somatosensory cortex using diffusion tensor imaging. Individual probabilistic tractography analyses were conducted in 100 subjects using the highest resolution data currently available. Tractography results were refined using a novel algorithm to objectively determine slice level thresholds that best minimized overlap between tracts while preserving tract volume...
March 14, 2017: Cerebral Cortex
https://www.readbyqxmd.com/read/28333631/segmenting-multi-source-images-using-hidden-markov-fields-with-copula-based-multivariate-statistical-distributions
#3
Jerome Lapuyade-Lahorgue, Jing-Hao Xue, Su Ruan
Nowadays, multi-source image acquisition attracts an increasing interest in many fields such as multi-modal medical image segmentation. Such acquisition aims at considering complementary information to perform image segmentation since the same scene has been observed by various types of images. However, strong dependency often exists between multi-source images. This dependency should be taken into account when we try to extract joint information for precisely making a decision. In order to statistically model this dependency between multiple sources, we propose a novel multi-source fusion method based on the Gaussian copula...
March 21, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
https://www.readbyqxmd.com/read/28333589/a-unified-theory-of-neuro-mri-data-shows-scale-free-nature-of-connectivity-modes
#4
Vitaly L Galinsky, Lawrence R Frank
A primary goal of many neuroimaging studies that use magnetic resonance imaging (MRI) is to deduce the structure-function relationships in the human brain using data from the three major neuro-MRI modalities: high-resolution anatomical, diffusion tensor imaging, and functional MRI. To date, the general procedure for analyzing these data is to combine the results derived independently from each of these modalities. In this article, we develop a new theoretical and computational approach for combining these different MRI modalities into a powerful and versatile framework that combines our recently developed methods for morphological shape analysis and segmentation, simultaneous local diffusion estimation and global tractography, and nonlinear and nongaussian spatial-temporal activation pattern classification and ranking, as well as our fast and accurate approach for nonlinear registration between modalities...
March 23, 2017: Neural Computation
https://www.readbyqxmd.com/read/28332039/combined-quantification-of-fatty-infiltration-t-1-relaxation-times-and-t-2-relaxation-times-in-normal-appearing-skeletal-muscle-of-controls-and-dystrophic-patients
#5
Benjamin Leporq, Arnaud Le Troter, Yann Le Fur, Emmanuelle Salort-Campana, Maxime Guye, Olivier Beuf, Shahram Attarian, David Bendahan
OBJECTIVES: To evaluate the combination of a fat-water separation method with an automated segmentation algorithm to quantify the intermuscular fatty-infiltrated fraction, the relaxation times, and the microscopic fatty infiltration in the normal-appearing muscle. MATERIALS AND METHODS: MR acquisitions were performed at 1.5T in seven patients with facio-scapulo-humeral dystrophy and eight controls. Disease severity was assessed using commonly used scales for the upper and lower limbs...
March 22, 2017: Magma
https://www.readbyqxmd.com/read/28330587/comparison-of-semi-automated-and-manual-methods-to-measure-the-volume-of-prostate-cancer-on-magnetic-resonance-imaging
#6
L Marin, M Ezziane, E Comperat, P Mozer, G Cancel-Tassin, J-F Coté, D Racoceanu, F Boudghene, O Lucidarme, O Cussenot, R Renard Penna
PURPOSE: The purpose of this study was to determine the accuracy of manual semi-automated and volumetric measurements to assess prostate cancer volume on multiparametric magnetic resonance imaging (MP-MRI) using whole-mount histopathology for validation. MATERIALS AND METHODS: We evaluated 30 consecutive men (median age, 65.7 years; interquartile range [IQR], 61.5-70.9 years) with a median prostatic specific antigen of 8.5ng/dL (IQR, 5.5-10.5ng/dL), who underwent MP-MRI before radical prostatectomy...
March 15, 2017: Diagnostic and Interventional Imaging
https://www.readbyqxmd.com/read/28329748/extensive-multilevel-split-laminotomy-for-debulking-a-cervicothoracolumbar-nondysraphic-intramedullary-spinal-cord-lipoma-in-a-2-month-old-infant
#7
Ha Son Nguyen, Sean Lew
INTRODUCTION: Laminectomy is the traditional approach for posterior exposure of the spinal canal for tumor resection. Another technique is split laminotomy, which entails the division and retraction of the spinous processes and laminae to access the thecal sac. This technique has been employed for small-segment exposures, but not extensively explored for long-segment exposures. CASE: A 2-month-old male presented with progressive right-leg plegia. MRI of the spine revealed a large, intramedullary spinal-cord lipoma extending from C6 to L5...
March 23, 2017: Pediatric Neurosurgery
https://www.readbyqxmd.com/read/28327941/degree-of-vascular-encasement-in-sphenoid-wing-meningiomas-predicts-postoperative-ischemic-complications
#8
D Jay McCracken, Raymond A Higginbotham, Jason H Boulter, Yuan Liu, John A Wells, Sameer H Halani, Amit M Saindane, Nelson M Oyesiku, Daniel L Barrow, Jeffrey J Olson
BACKGROUND: Sphenoid wing meningiomas (SWMs) can encase arteries of the circle of Willis, increasing their susceptibility to intraoperative vascular injury and severe ischemic complications. OBJECTIVE: To demonstrate the effect of circumferential vascular encasement in SWM on postoperative ischemia. METHODS: A retrospective review of 75 patients surgically treated for SWM from 2009 to 2015 was undertaken to determine the degree of circumferential vascular encasement (0°-360°) as assessed by preoperative magnetic resonance imaging (MRI)...
January 28, 2017: Neurosurgery
https://www.readbyqxmd.com/read/28327564/quantification-of-whole-body-and-segmental-skeletal-muscle-mass-using-phase-sensitive-8-electrode-medical-bioelectrical-impedance-devices
#9
A Bosy-Westphal, B Jensen, W Braun, M Pourhassan, D Gallagher, M J Müller
BACKGROUND/OBJECTIVES: Bioelectrical impedance analysis (BIA) provides noninvasive measures of skeletal muscle mass (SMM) and visceral adipose tissue (VAT). This study (i) analyzes the impact of conventional wrist-ankle vs segmental technology and standing vs supine position on BIA equations and (ii) compares BIA validation against magnetic resonance imaging (MRI) and dual X-ray absorptiometry (DXA). SUBJECTS/METHODS: One hundred and thirty-six healthy Caucasian adults (70 men, 66 women; age 40±12 years) were measured by a phase-sensitive multifrequency BIA (seca medical body composition analyzers 515 and 525)...
March 22, 2017: European Journal of Clinical Nutrition
https://www.readbyqxmd.com/read/28324943/overcoming-spatio-temporal-limitations-using-dynamically-scaled-in-vitro-pc-mri-a-flow-field-comparison-to-true-scale-computer-simulations-of-idealized-stented-and-patient-specific-left-main-bifurcations
#10
Susann Beier, John Ormiston, Mark Webster, John Cater, Stuart Norris, Pau Medrano-Gracia, Alistair Young, Kathleen Gilbert, Brett Cowan
The majority of patients with angina or heart failure have coronary artery disease. Left main bifurcations are particularly susceptible to pathological narrowing. Flow is a major factor of atheroma development, but limitations in imaging technology such as spatio-temporal resolution, signal-to-noise ratio (SNRv), and imaging artefacts prevent in vivo investigations. Computational fluid dynamics (CFD) modelling is a common numerical approach to study flow, but it requires a cautious and rigorous application for meaningful results...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28323377/accuracy-of-pdff-estimation-by-magnitude-based-and-complex-based-mri-in-children-with-mr-spectroscopy-as-a-reference
#11
William M Haufe, Tanya Wolfson, Catherine A Hooker, Jonathan C Hooker, Yesenia Covarrubias, Alex N Schlein, Gavin Hamilton, Michael S Middleton, Jorge E Angeles, Diego Hernando, Scott B Reeder, Jeffrey B Schwimmer, Claude B Sirlin
PURPOSE: To assess and compare the accuracy of magnitude-based magnetic resonance imaging (MRI-M) and complex-based MRI (MRI-C) for estimating hepatic proton density fat fraction (PDFF) in children, using MR spectroscopy (MRS) as the reference standard. A secondary aim was to assess the agreement between MRI-M and MRI-C. MATERIALS AND METHODS: This was a HIPAA-compliant, retrospective analysis of data collected in children enrolled in prospective, Institutional Review Board (IRB)-approved studies between 2012 and 2014...
March 21, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28323127/bi-phase-age-related-brain-gray-matter-magnetic-resonance-t1%C3%AF-relaxation-time-change-in-adults
#12
Yáo T Li, Hua Huang, Zhizheng Zhuo, Pu-Xuan Lu, Weitian Chen, Yì Xiáng J Wáng
OBJECTIVES: To investigate normative value and age-related change of brain magnetic resonance T1ρ relaxation at 1.5T. METHODS: This study was approved by the local ethical committee with participants' written consent obtained. There were 42 adults healthy volunteers, including 20 males (age: 41±16 (mean±standard deviation) years, range: 22-68years,) and 22 females (age: 39±15years, range: 21-62years). MRI was performed at 1.5T using 3D fluid suppressed turbo spin echo sequence...
March 16, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28321681/machine-learning-of-the-spatio-temporal-characteristics-of-echocardiographic-deformation-curves-for-infarct-classification
#13
Mahdi Tabassian, Martino Alessandrini, Lieven Herbots, Oana Mirea, Efstathios D Pagourelias, Ruta Jasaityte, Jan Engvall, Luca De Marchi, Guido Masetti, Jan D'hooge
The aim of this study was to analyze the whole temporal profiles of the segmental deformation curves of the left ventricle (LV) and describe their interrelations to obtain more detailed information concerning global LV function in order to be able to identify abnormal changes in LV mechanics. The temporal characteristics of the segmental LV deformation curves were compactly described using an efficient decomposition into major patterns of variation through a statistical method, called Principal Component Analysis (PCA)...
March 20, 2017: International Journal of Cardiovascular Imaging
https://www.readbyqxmd.com/read/28321567/adjacent-segment-pathology-natural-history-or-effect-of-anterior-cervical-discectomy-and-fusion-a-10-year-follow-up-radiological-multicenter-study-using-an-evaluation-scale-of-the-ageing-spine
#14
Alessandro Pesce, Venceslao Wierzbicki, Emanuele Piccione, Alessandro Frati, Antonino Raco, Riccardo Caruso
PURPOSE: Aim of this study is to compare late degenerative MRI changes in a subset of patients operated on with ACDF to a second subset of patients presenting indication to ACDF but never operated on. METHODS: Patients from both subgroups received surgical indication according to the same criteria. Both subgroups underwent a cervical spine MRI in 2004-2005 and 10 years later in 2015. These MRI scans were retrospectively evaluated with a cervical spine ageing scale...
March 20, 2017: European Journal of Orthopaedic Surgery & Traumatology: Orthopédie Traumatologie
https://www.readbyqxmd.com/read/28321524/what-are-the-true-volumes-of-sega-tumors-reliability-of-planimetric-and-popular-semi-automated-image-segmentation-methods
#15
Konrad Stawiski, Joanna Trelińska, Dobromiła Baranska, Iwona Dachowska, Katarzyna Kotulska, Sergiusz Jóźwiak, Wojciech Fendler, Wojciech Młynarski
OBJECTIVE: To evaluate the reliability of the standard planimetric methodology of volumetric analysis and three different open-source semi-automated approaches of brain tumor segmentation. MATERIALS AND METHODS: The volumes of subependymal giant cell astrocytomas (SEGA) examined by 30 MRI studies of 10 patients from a previous everolimus-related trial (EMINENTS study) were estimated using four methods: planimetric method (modified MacDonald ellipsoid method), ITK-Snap (pixel clustering, geodesic active contours, region competition methods), 3D Slicer (level-set thresholding), and NIRFast (k-means clustering, Markov random fields)...
March 20, 2017: Magma
https://www.readbyqxmd.com/read/28321371/anatomic-variations-in-pituitary-endocrinopathies-implications-for-the-surgical-corridor
#16
Edward C Kuan, Frederick Yoo, Won Kim, Karam W Badran, Thomas E Heineman, Ali R Sepahdari, Marvin Bergsneider, Marilene B Wang
Objectives/Hypotheses Functioning pituitary adenomas may produce endocrinopathies such as acromegaly and Cushing syndrome. Both conditions lead to characteristic anatomic variations as a result of hormonally induced abnormal soft tissue deposition. We evaluate the anatomic differences between acromegalics and Cushing disease patients and compare these dimensions to controls. Design Radiographic review of preoperative magnetic resonance images (MRI) of the pituitary gland. Setting Tertiary academic medical center...
April 2017: Journal of Neurological Surgery. Part B, Skull Base
https://www.readbyqxmd.com/read/28317116/anatomical-segmentation-of-the-human-medial-prefrontal-cortex
#17
M Córcoles-Parada, Ncj Müller, M Ubero, V M Serrano-Del-Pueblo, F Mansilla, P Marcos-Rabal, E Artacho-Pérula, M Dresler, R Insausti, G Fernández, M Muñoz-López
The medial prefrontal areas 32, 24, 14, and 25 (mPFC) form part of the limbic memory system, but little is known about their functional specialization in humans. To add anatomical precision to structural and functional MRI data, we aimed to identify these mPFC subareas in histological preparations of human brain tissue, determine sulci most consistently related with mPFC areal boundaries, and use these sulci to delineate mPFC areas in MRIs. To achieve this, we obtained 3D MRI data from 11 ex vivo hemispheres and processed them for cyto- and myelo-architectonic analysis...
March 20, 2017: Journal of Comparative Neurology
https://www.readbyqxmd.com/read/28316992/a-combined-random-forests-and-active-contour-model-approach-for-fully-automatic-segmentation-of-the-left-atrium-in-volumetric-mri
#18
Chao Ma, Gongning Luo, Kuanquan Wang
Segmentation of the left atrium (LA) from cardiac magnetic resonance imaging (MRI) datasets is of great importance for image guided atrial fibrillation ablation, LA fibrosis quantification, and cardiac biophysical modelling. However, automated LA segmentation from cardiac MRI is challenging due to limited image resolution, considerable variability in anatomical structures across subjects, and dynamic motion of the heart. In this work, we propose a combined random forests (RFs) and active contour model (ACM) approach for fully automatic segmentation of the LA from cardiac volumetric MRI...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28315882/comparison-of-total-kidney-volume-quantification-methods-in-autosomal-dominant-polycystic-disease-for-a-comprehensive-disease-assessment
#19
Dario Turco, Marco Busutti, Renzo Mignani, Riccardo Magistroni, Cristiana Corsi
BACKGROUND: In recent times, the scientific community has been showing increasing interest in the treatments aimed at slowing the progression of the autosomal dominant polycystic kidney disease (ADPKD). Therefore, in this paper, we test and evaluate the performance of several available methods for total kidney volume (TKV) computation in ADPKD patients - from echography to MRI - in order to optimize patient classification. METHODS: Two methods based on geometric assumptions (mid-slice [MS], ellipsoid [EL]) and a third one on true contour detection were tested on 40 ADPKD patients at different disease stage using MRI...
March 18, 2017: American Journal of Nephrology
https://www.readbyqxmd.com/read/28315740/population-based-mri-and-dti-templates-of-the-adult-ferret-brain-and-tools-for-voxelwise-analysis
#20
E B Hutchinson, S C Schwerin, K L Radomski, N Sadeghi, J Jenkins, M E Komlosh, M O Irfanoglu, S L Juliano, C Pierpaoli
Non-invasive imaging has the potential to play a crucial role in the characterization and translation of experimental animal models to investigate human brain development and disorders, especially when employed to study animal models that more accurately represent features of human neuroanatomy. The purpose of this study was to build and make available MRI and DTI templates and analysis tools for the ferret brain as the ferret is a well-suited species for pre-clinical MRI studies with folded cortical surface, relatively high white matter volume and body dimensions that allow imaging with pre-clinical MRI scanners...
March 15, 2017: NeuroImage
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