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Segmented MRI

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https://www.readbyqxmd.com/read/28646330/-imaging-of-vessels-supplying-the-brain
#1
REVIEW
S M Schellong, N Abolmaali, B Voigts, C Stelzner
Nowadays, several technically validated modalities are available for imaging both the extracranial and intracranial segments of arteries supplying blood to the brain. In the acute stroke setting, computed tomography (CT) angiography is of utmost importance because it provides the key diagnostic criteria indicative for the use of catheter-based recanalization techniques. Ultrasound imaging of extracranial arteries is most suitable for detecting an underlying stenosis of the internal carotid artery (ICA) in patients with stroke, transient ischemic attacks (TIA), retinal vessel occlusion and amaurosis fugax...
June 23, 2017: Der Internist
https://www.readbyqxmd.com/read/28642629/improved-brain-tumor-segmentation-by-utilizing-tumor-growth-model-in-longitudinal-brain-mri
#2
Linmin Pei, Syed M S Reza, Wei Li, Christos Davatzikos, Khan M Iftekharuddin
In this work, we propose a novel method to improve texture based tumor segmentation by fusing cell density patterns that are generated from tumor growth modeling. In order to model tumor growth, we solve the reaction-diffusion equation by using Lattice-Boltzmann method (LBM). Computational tumor growth modeling obtains the cell density distribution that potentially indicates the predicted tissue locations in the brain over time. The density patterns is then considered as novel features along with other texture (such as fractal, and multifractal Brownian motion (mBm)), and intensity features in MRI for improved brain tumor segmentation...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28642263/volumetric-analysis-from-a-harmonized-multisite-brain-mri-study-of-a-single-subject-with-multiple-sclerosis
#3
R T Shinohara, J Oh, G Nair, P A Calabresi, C Davatzikos, J Doshi, R G Henry, G Kim, K A Linn, N Papinutto, D Pelletier, D L Pham, D S Reich, W Rooney, S Roy, W Stern, S Tummala, F Yousuf, A Zhu, N L Sicotte, R Bakshi
BACKGROUND AND PURPOSE: MR imaging can be used to measure structural changes in the brains of individuals with multiple sclerosis and is essential for diagnosis, longitudinal monitoring, and therapy evaluation. The North American Imaging in Multiple Sclerosis Cooperative steering committee developed a uniform high-resolution 3T MR imaging protocol relevant to the quantification of cerebral lesions and atrophy and implemented it at 7 sites across the United States. To assess intersite variability in scan data, we imaged a volunteer with relapsing-remitting MS with a scan-rescan at each site...
June 22, 2017: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/28641952/the-effect-of-tissue-segmented-attenuation-maps-on-pet-quantification-with-a-special-focus-on-large-arteries
#4
A Mota-Cobian, J C Alonso-Farto, L Fernández-Friera, J Sánchez-González, B López-Melgar, L J Jiménez-Borreguero, V Fuster, J Ruiz-Cabello, S España
OBJECTIVES: Accuracy on quantitative PET image analysis relies on the correct application of attenuation correction which is one of the major challenges for PET/MRI that remains to be solved. The purpose of this study is to evaluate the effect of MRI-based attenuation maps and the use of flexible coils on the quantitative accuracy of PET images with a special focus on large arteries. MATERIALS AND METHODS: PET/CT data from eight oncologic patients was used. PET data was reconstructed using attenuation maps with different level of detail emulating several approaches available on current PET/MRI scanners...
June 19, 2017: Revista Española de Medicina Nuclear e Imagen Molecular
https://www.readbyqxmd.com/read/28641769/reduction-of-pk11195-uptake-observed-in-multiple-sclerosis-lesions-after-natalizumab-initiation
#5
Ulrike W Kaunzner, Yeona Kang, Elizabeth Monohan, Paresh J Kothari, Nancy Nealon, Jai Perumal, Timothy Vartanian, Amy Kuceyeski, Shankar Vallabhajosula, P David Mozley, Claire S Riley, Stephen M Newman, Susan A Gauthier
OBJECTIVE: The objective of this study is to longitudinally analyze the uptake of [(11)C]PK11195-PET in multiple sclerosis patients after 3 and 6 months of natalizumab treatment. METHODS: Eighteen MS patients, starting treatment with monocloncal anti-VLA-4, were enrolled in a longitudinal PK-PET study. PK uptake was quantified by volume of distribution (VT) calculation using image-derived input function at baseline, 3 and 6 months. Pharmacokinetic quantification was done using a segmented MRI, and selected areas included white matter, gadolinium enhancing lesions, non-enhancing lesions, cortical grey matter and thalamus...
July 2017: Multiple Sclerosis and related Disorders
https://www.readbyqxmd.com/read/28640521/pet-mri-for-evaluating-subclinical-inflammation-of-ulcerative-colitis
#6
I-Lun Shih, Shu-Chen Wei, Rouh-Fang Yen, Chin-Chen Chang, Chi-Lun Ko, Been-Ren Lin, Chia-Tung Shun, Kao-Lang Liu, Jau-Min Wong, Yeun-Chung Chang
PURPOSE: To explore the utility of integrated positron emission tomography (PET) / magnetic resonance imaging (MRI) for evaluating subclinical inflammation in patients with ulcerative colitis (UC). MATERIALS AND METHODS: This prospective study was approved by the Institutional Review Board and informed consent was obtained. Between November 2015 and April 2016, 19 consecutive patients with UC in clinical remission were enrolled. These patients underwent 18F-fluorodeoxyglucose PET/MRI (3T) and colonoscopy...
June 22, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28640143/relationship-between-postural-instability-and-subcortical-volume-loss-in-alzheimer-s-disease
#7
Young-Wook Lee, Hyung Lee, In-Sung Chung, Hyon-Ah Yi
The relationship between postural instability and subcortical structure in AD has received less attention. The aims of this study were to assess whether there are differences in the ability to control balance between Alzheimer's disease (AD) and controls, and to investigate the association between subcortical gray matter volumes and postural instability in AD.We enrolled 107 consecutive AD patients and 37 controls. All participants underwent detailed neuropsychological evaluations, T1-weighted MRI at 3 T, and posture assessment using computerized dynamic posturography...
June 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28639048/evaluating-anorexia-related-brain-atrophy-using-mp2rage-based-morphometry
#8
José Boto, Georgios Gkinis, Alexis Roche, Tobias Kober, Bénédicte Maréchal, Nadia Ortiz, Karl-Olof Lövblad, François Lazeyras, Maria Isabel Vargas
AIM: To evaluate brain atrophy in anorexic patients by automated cerebral segmentation with the magnetization-prepared 2 rapid acquisition gradient echo (MP2RAGE) MRI sequence. MATERIAL AND METHODS: Twenty patients (female; mean age, 27.9 years), presenting consecutively for brain MRI between August 2014-December 2016 with clinical suspicion of anorexia nervosa and BMI<18.5 kg/m(2) were included. Controls were ten healthy females (mean age, 26.5 years). Automated brain morphometry was performed based on MP2RAGE...
June 21, 2017: European Radiology
https://www.readbyqxmd.com/read/28638946/nerve-atrophy-in-trigeminal-neuralgia-due-to-neurovascular-compression-and-its-association-with-surgical-outcomes-after-microvascular-decompression
#9
Jian Cheng, Jinli Meng, Wenke Liu, Heng Zhang, Xuhui Hui, Ding Lei
BACKGROUND: Idiopathic trigeminal neuralgia (TN) is caused by neurovascular compression and is often related to morphological changes in the trigeminal nerve. The aim of this study was to quantitatively measure atrophic changes of trigeminal nerves in patients with TN, and to further investigate whether nerve atrophy affected the efficacy of microvascular decompression (MVD). METHODS: We conducted a prospective case-control study of 60 consecutive patients with TN and 30 sex- and age-matched healthy controls...
June 21, 2017: Acta Neurochirurgica
https://www.readbyqxmd.com/read/28634513/correlation-of-lumbar-lateral-recess-stenosis-in-magnetic-resonance-imaging-and-clinical-symptoms
#10
Annina Splettstößer, M Fawad Khan, Bernd Zimmermann, Thomas J Vogl, Hanns Ackermann, Marcus Middendorp, Adel Maataoui
AIM: To assess the correlation of lateral recess stenosis (LRS) of lumbar segments L4/5 and L5/S1 and the Oswestry Disability Index (ODI). METHODS: Nine hundred and twenty-seven patients with history of low back pain were included in this uncontrolled study. On magnetic resonance images (MRI) the lateral recesses (LR) at lumbar levels L4/5 and L5/S1 were evaluated and each nerve root was classified into a 4-point grading scale (Grade 0-3) as normal, not deviated, deviated or compressed...
May 28, 2017: World Journal of Radiology
https://www.readbyqxmd.com/read/28632492/is-the-location-of-the-signal-intensity-weighted-centroid-a-reliable-measurement-of-fluid-displacement-within-the-disc
#11
Vahid Abdollah, Eric C Parent, Michele C Battié
Degenerated discs have shorter T2-relaxation time and lower MR signal. The location of the signal-intensity-weighted-centroid reflects the water distribution within a region-of-interest (ROI). This study compared the reliability of the location of the signal-intensity-weighted-centroid to mean signal intensity and area measurements. L4-L5 and L5-S1 discs were measured on 43 mid-sagittal T2-weighted 3T MRI images in adults with back pain. One rater analysed images twice and another once, blinded to measurements...
June 20, 2017: Biomedizinische Technik. Biomedical Engineering
https://www.readbyqxmd.com/read/28631535/high-resolution-magnetic-resonance-imaging-for-exposing-facial-nerve-zonal-vulnerability-to-microbleeds-a-rare-cause-of-facial-palsy
#12
Charlie Chia-Tsong Hsu, Dalveer Singh, Trevor William Watkins, Gigi Nga Chi Kwan, Sachintha Hapugoda
Background We report a case of hypertensive microbleeds strategically located at the attached segment (AS) and root entry zone (REZ) at the left facial nerve causing facial paralysis. Case Report A 60-year-old woman presented with sudden onset left facial paralysis. Medical history was significant for poorly controlled hypertension secondary to bilateral adrenal hyperplasia (primary hyperaldosteronism). The patient was initially treated for presumptive Bell's palsy. Subsequent magnetic resonance imaging of the brain and internal auditory canal showed two microbleeds at the left cerebellopontine angle...
January 1, 2017: Neuroradiology Journal
https://www.readbyqxmd.com/read/28630885/bayesian-framework-inspired-no-reference-region-of-interest-quality-measure-for-brain-mri-images
#13
Michael Osadebey, Marius Pedersen, Douglas Arnold, Katrina Wendel-Mitoraj
We describe a postacquisition, attribute-based quality assessment method for brain magnetic resonance imaging (MRI) images. It is based on the application of Bayes theory to the relationship between entropy and image quality attributes. The entropy feature image of a slice is segmented into low- and high-entropy regions. For each entropy region, there are three separate observations of contrast, standard deviation, and sharpness quality attributes. A quality index for a quality attribute is the posterior probability of an entropy region given any corresponding region in a feature image where quality attribute is observed...
April 2017: Journal of Medical Imaging
https://www.readbyqxmd.com/read/28628751/comparison-between-line-and-surface-mesh-models-to-represent-the-rotator-cuff-muscle-geometry-in-musculoskeletal-models
#14
Marion Hoffmann, Diane Haering, Mickaël Begon
Accurate muscle geometry (muscle length and moment arm) is required to estimate muscle function when using musculoskeletal modelling. In shoulder, muscles are often modelled as a collection of independent line segments, leading to non-physiological muscles trajectory, especially for the rotator cuff muscles. To prevent this, a surface mesh model was developed and validated against 7 MRI positions in one participant. Mean moment arm errors was 11.4% for the line vs. 8.8% for the mesh model. While the model with independent lines led to some non-physiological trajectories, the mesh model gave lower misestimations of muscle lengths and moment arms...
June 19, 2017: Computer Methods in Biomechanics and Biomedical Engineering
https://www.readbyqxmd.com/read/28626842/automated-segmentation-of-knee-mri-using-hierarchical-classifiers-and-just-enough-interaction-based-learning-data-from-osteoarthritis-initiative
#15
Satyananda Kashyap, Ipek Oguz, Honghai Zhang, Milan Sonka
We present a fully automated learning-based approach for segmenting knee cartilage in presence of osteoarthritis (OA). The algorithm employs a hierarchical set of two random forest classifiers. The first is a neighborhood approximation forest, the output probability map of which is utilized as a feature set for the second random forest (RF) classifier. The output probabilities of the hierarchical approach are used as cost functions in a Layered Optimal Graph Segmentation of Multiple Objects and Surfaces (LOGISMOS)...
October 2016: Medical Image Computing and Computer-assisted Intervention: MICCAI ..
https://www.readbyqxmd.com/read/28626412/congenital-bilateral-c2-transverse-foramina-stenosis-causing-adult-onset-vertebrobasilar-insufficiency-and-posterior-circulation-stroke
#16
Ajeet Gordhan, Catherine Lockhart
Vertebrobasilar insufficiency leading to posterior circulation infarcts caused by congenital hypoplasia of the bilateral transverse foramina at the C2 level, affecting the caliber and flow of the bilateral distal cervical vertebral arteries in an adult, has not been previously reported. A 41-year-old male presented with episodic dizziness for a period of 1 year prior to consultation. Computed tomography angiography of the head and neck demonstrated congenital hypoplasia of the bilateral C2 transverse foramina, with absence of the vertebral arteries in each of the foramina and collateral reconstitution of diminutive intracranial vertebral artery segments...
May 2017: Case Reports in Neurology
https://www.readbyqxmd.com/read/28626291/machine-learning-in-a-graph-framework-for-subcortical-segmentation
#17
Zhihui Guo, Satyananda Kashyap, Milan Sonka, Ipek Oguz
Automated and reliable segmentation of subcortical structures from human brain magnetic resonance images is of great importance for volumetric and shape analyses in quantitative neuroimaging studies. However, poor boundary contrast and variable shape of these structures make the automated segmentation a tough task. We propose a 3D graph-based machine learning method, called LOGISMOS-RF, to segment the caudate and the putamen from brain MRI scans in a robust and accurate way. An atlas-based tissue classification and bias-field correction method is applied to the images to generate an initial segmentation for each structure...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28626186/reversible-cerebral-vasoconstriction-syndrome-presenting-with-transient-global-amnesia
#18
Kenji Isahaya, Kensuke Shinohara, Masashi Akamatu, Takahiro Shimizu, Kenzo Sakurai, Makoto Shiraishi, Hisanao Akiyama, Yasuhiro Hasegawa
A 65-year-old man who had been diagnosed with transient global amnesia (TGA) 15 years previously was admitted to hospital with complaints of amnesia and headache. His symptoms improved on day-2. The initial brain MRI and electroencephalography findings were normal. He was diagnosed with a recurrence of TGA and discharged. However, he returned with right leg weakness and complained of a thunderclap headache. MRI demonstrated subarachnoid hemorrhage and multifocal segmental narrowing of the left posterior cerebral artery (PCA) and large intracranial arteries, and he was diagnosed with reversible cerebral vasoconstriction syndrome (RCVS)...
2017: Internal Medicine
https://www.readbyqxmd.com/read/28624016/longitudinal-change-in-patellofemoral-cartilage-thickness-cartilage-t2-relaxation-times-and-subchondral-bone-plate-area-in-adolescent-vs-mature-athletes
#19
Adam G Culvenor, Wolfgang Wirth, Susanne Maschek, Heide Boeth, Gerd Diederichs, Georg Duda, Felix Eckstein
OBJECTIVE: Patellofemoral cartilage changes have been evaluated in knee trauma and osteoarthritis; however, little is known about changes in patellar and trochlear cartilage thickness, T2 relaxation-time and subchondral bone plate area (tAB) during growth. Our prospective study aimed to explore longitudinal change in patellofemoral cartilage thickness, T2 and tAB in adolescent athletes, and to compare these data with those of mature (i.e., adult) athletes. MATERIALS AND METHODS: 20 adolescent (age 16±1years) and 20 mature (46±5years) volleyball players were studied over 2-years (10 men and 10 women each group)...
July 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28623409/evaluation-of-bone-viability-in-patients-after-girdlestone-arthroplasty-comparison-of-bone-spect-ct-and-mri
#20
G Diederichs, P Hoppe, F Collettini, G Wassilew, B Hamm, W Brenner, M R Makowski
PURPOSE: To test the diagnostic performance of bone SPECT/CT and MRI for the evaluation of bone viability in patients after girdlestone-arthroplasty with histopathology used as gold standard. MATERIALS AND METHODS: In this cross-sectional study, patients after girdlestone-arthroplasty were imaged with single-photon-emission-computed-tomography/computed-tomography (SPECT/CT) bone-scans using 99mTc-DPD. Additionally, 1.5 T MRI was performed with turbo-inversion-recovery-magnitude (TIRM), contrast-enhanced T1-fat sat (FS) and T1-mapping...
June 16, 2017: Skeletal Radiology
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