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https://www.readbyqxmd.com/read/28424605/white-matter-integrity-and-treatment-based-change-in-speech-performance-in-minimally-verbal-children-with-autism-spectrum-disorder
#1
Karen Chenausky, Julius Kernbach, Andrea Norton, Gottfried Schlaug
We investigated the relationship between imaging variables for two language/speech-motor tracts and speech fluency variables in 10 minimally verbal (MV) children with autism. Specifically, we tested whether measures of white matter integrity-fractional anisotropy (FA) of the arcuate fasciculus (AF) and frontal aslant tract (FAT)-were related to change in percent syllable-initial consonants correct, percent items responded to, and percent syllable insertion errors (from best baseline to post 25 treatment sessions)...
2017: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/28391596/technical-note-is-bulk-electron-density-assignment-appropriate-for-mri-only-based-treatment-planning-for-lung-cancer
#2
Phil Prior, Xinfeng Chen, Elizabeth Gore, Candice Johnstone, X Allen Li
PURPOSE: MRI-based treatment planning in radiation therapy (RT) is prohibitive, in part, due to the lack of electron density (ED) information within the image. The dosimetric differences between MRI- and CT-based planning for intensity modulated RT (IMRT) of lung cancer were investigated to assess the appropriateness of bulk ED assignment. METHODS: Planning CTs acquired for six representative lung cancer patients were used to generate bulk ED IMRT plans. To avoid the effect of anatomic differences between CT and MRI, "simulated MRI-based plans" were generated by forcing the relative ED (rED) to water on CT-delineated structures using organ specific values from the ICRU Report 46 and using the mean rED value of the internal target volume (ITV) from the planning CT...
April 9, 2017: Medical Physics
https://www.readbyqxmd.com/read/28385584/a-study-of-the-clinical-utility-of-a-20-minute-secretin-stimulated-endoscopic-pancreas-function-test-and-performance-according-to-clinical-variables
#3
Luis F Lara, Morihito Takita, James S Burdick, Daniel C DeMarco, Ronnie R Pimentel, Tolga Erim, Marlon F Levy
BACKGROUND & AIMS: Direct pancreas juice testing of bicarbonate, lipase, or trypsin after stimulation by secretin or cholecystokinin (CCK) is used to determine exocrine function, a surrogate for diagnosing chronic pancreatitis (CP). Endoscopic pancreas function tests (ePFT) where a peak bicarbonate concentration (PBC) ≥80 mEq/L in pancreas juice is considered normal are now used more frequently. In this ePFT aspirates start 35 minutes after secretin administration because pancreas output peaks 30 minutes after secretagogue administration...
April 3, 2017: Gastrointestinal Endoscopy
https://www.readbyqxmd.com/read/28369170/supervised-multiblock-sparse-multivariable-analysis-with-application-to-multimodal-brain-imaging-genetics
#4
Atsushi Kawaguchi, Fumio Yamashita
This article proposes a procedure for describing the relationship between high-dimensional data sets, such as multimodal brain images and genetic data. We propose a supervised technique to incorporate the clinical outcome to determine a score, which is a linear combination of variables with hieratical structures to multimodalities. This approach is expected to obtain interpretable and predictive scores. The proposed method was applied to a study of Alzheimer's disease (AD). We propose a diagnostic method for AD that involves using whole-brain magnetic resonance imaging (MRI) and positron emission tomography (PET), and we select effective brain regions for the diagnostic probability and investigate the genome-wide association with the regions using single nucleotide polymorphisms (SNPs)...
March 19, 2017: Biostatistics
https://www.readbyqxmd.com/read/28367541/patch-based-synthesis-of-whole-head-mr-images-application-to-epi-distortion-correction
#5
Snehashis Roy, Yi-Yu Chou, Amod Jog, John A Butman, Dzung L Pham
Different magnetic resonance imaging pulse sequences are used to generate image contrasts based on physical properties of tissues, which provide different and often complementary information about them. Therefore multiple image contrasts are useful for multimodal analysis of medical images. Often, medical image processing algorithms are optimized for particular image contrasts. If a desirable contrast is unavailable, contrast synthesis (or modality synthesis) methods try to "synthesize" the unavailable constrasts from the available ones...
October 2016: Simul Synth Med Imaging (2016)
https://www.readbyqxmd.com/read/28345960/graft-utilization-in-the-bridging-reconstruction-of-irreparable-rotator-cuff-tears-a-systematic-review
#6
Matthew R Lewington, Devin P Ferguson, T Duncan Smith, Robert Burks, Catherine Coady, Ivan Ho-Bun Wong
BACKGROUND: Rotator cuff tears are one of the most common conditions affecting the shoulder. Because of the difficulty in managing massive rotator cuff tears and the inability of standard techniques to prevent arthropathy, surgeons have developed several novel techniques to improve outcomes and ideally alter the natural history. PURPOSE: To systematically review the existing literature and analyze reported outcomes to evaluate the effectiveness of using a bridging graft reconstruction technique to treat large to massive irreparable rotator cuff tears...
March 1, 2017: American Journal of Sports Medicine
https://www.readbyqxmd.com/read/28337429/investigating-cardiac-motion-patterns-using-synthetic-high-resolution-3d-cardiovascular-magnetic-resonance-images-and-statistical-shape-analysis
#7
Benedetta Biffi, Jan L Bruse, Maria A Zuluaga, Hopewell N Ntsinjana, Andrew M Taylor, Silvia Schievano
Diagnosis of ventricular dysfunction in congenital heart disease is more and more based on medical imaging, which allows investigation of abnormal cardiac morphology and correlated abnormal function. Although analysis of 2D images represents the clinical standard, novel tools performing automatic processing of 3D images are becoming available, providing more detailed and comprehensive information than simple 2D morphometry. Among these, statistical shape analysis (SSA) allows a consistent and quantitative description of a population of complex shapes, as a way to detect novel biomarkers, ultimately improving diagnosis and pathology understanding...
2017: Frontiers in Pediatrics
https://www.readbyqxmd.com/read/28337030/prenatal-steroid-administration-leads-to-adult-pericardial-and-hepatic-steatosis-in-male-baboons
#8
A H Kuo, J Li, C Li, H F Huber, M Schwab, P W Nathanielsz, G D Clarke
Developmental programming studies indicate that glucocorticoids modify fetal development. We hypothesized that administration of the synthetic glucocorticoid (sGC) betamethasone to pregnant baboons at doses and stages of fetal life equivalent to human obstetric practice to decrease premature offspring morbidity and mortality, programs lipid metabolism. In 10-year-old male baboons (human equivalent 40) exposed in fetal life to betamethasone or saline, we quantified pericardial fat and hepatic lipid content with magnetic resonance imaging and spectroscopy...
March 24, 2017: International Journal of Obesity: Journal of the International Association for the Study of Obesity
https://www.readbyqxmd.com/read/28321901/a-pneumatic-phantom-for-mimicking-respiration-induced-artifacts-in-spinal-mri
#9
Philippe De Tillieux, Ryan Topfer, Alexandru Foias, Iris Leroux, Imanne El Maâchi, Hugues Leblond, Nikola Stikov, Julien Cohen-Adad
PURPOSE: To design a phantom capable of mimicking human respiration to serve as a testing platform for correction of the static and time-evolving magnetic field distortions typically encountered in MRI of the spinal cord. METHODS: An inflation system to mimic the air variation of the human lungs was constructed. The inflation system was linked to a phantom containing synthetic lungs and an ex vivo human spine. The relationship between air pressure and phantom lung volume was evaluated via imaging experiment...
March 20, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28320831/interference-of-the-t-cell-and-antigen-presenting-cell-costimulatory-pathway-using-ctla4-ig-abatacept-prevents-staphylococcal-enterotoxin-b-pathology
#10
Sarah J C Whitfield, Chris Taylor, Jane E Risdall, Gareth D Griffiths, James T A Jones, E Diane Williamson, Sjoerd Rijpkema, Luisa Saraiva, Sandrine Vessillier, A Christopher Green, Alun J Carter
Staphylococcal enterotoxin B (SEB) is a bacterial superantigen that binds the receptors in the APC/T cell synapse and causes increased proliferation of T cells and a cytokine storm syndrome in vivo. Exposure to the toxin can be lethal and cause significant pathology in humans. The lack of effective therapies for SEB exposure remains an area of concern, particularly in scenarios of acute mass casualties. We hypothesized that blockade of the T cell costimulatory signal by the CTLA4-Ig synthetic protein (abatacept) could prevent SEB-dependent pathology...
March 20, 2017: Journal of Immunology: Official Journal of the American Association of Immunologists
https://www.readbyqxmd.com/read/28320682/deformable-registration-based-super-resolution-for-isotropic-reconstruction-of-4d-mri-volumes
#11
Geetha Soujanya Chilla, Cher Heng Tan, Chueh Loo Poh
Multi-plane super-resolution (SR) has been widely employed for resolution improvement of MR images. However, this has mostly been limited to MRI acquisitions with rigid motion. In cases of non-rigid motion, volumes are usually pre-registered using deformable registration methods before SR reconstruction. The pre-registered images are then used as input for the SR reconstruction. Since deformable registration involves smoothening of the inputs, using pre-registered inputs could lead to loss in information in SR reconstructions...
March 13, 2017: IEEE Journal of Biomedical and Health Informatics
https://www.readbyqxmd.com/read/28306555/assessment-of-dosimetric-impact-of-system-specific-geometric-distortion-in-an-mri-only-based-radiotherapy-workflow-for-prostate
#12
C Gustafsson, F Nordström, E Persson, J Brynolfsson, L E Olsson
Dosimetric errors in a magnetic resonance imaging (MRI) only radiotherapy workflow may be caused by system specific geometric distortion from MRI. The aim of this study was to evaluate the impact on planned dose distribution and delineated structures for prostate patients, originating from this distortion. A method was developed, in which computer tomography (CT) images were distorted using the MRI distortion field. The displacement map for an optimized MRI treatment planning sequence was measured using a dedicated phantom in a 3 T MRI system...
April 21, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28306550/female-pelvic-synthetic-ct-generation-based-on-joint-intensity-and-shape-analysis
#13
Lianli Liu, Shruti Jolly, Yue Cao, Karen Vineberg, Jeffrey A Fessler, James M Balter
Using MRI for radiotherapy treatment planning and image guidance is appealing as it provides superior soft tissue information over CT scans and avoids possible systematic errors introduced by aligning MR to CT images. This study presents a method that generates Synthetic CT (MRCT) volumes by performing probabilistic tissue classification of voxels from MRI data using a single imaging sequence (T1 Dixon). The intensity overlap between different tissues on MR images, a major challenge for voxel-based MRCT generation methods, is addressed by adding bone shape information to an intensity-based classification scheme...
April 21, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28306547/synthetic-ct-for-mri-based-liver-stereotactic-body-radiotherapy-treatment-planning
#14
Jeremy S Bredfeldt, Lianli Liu, Mary Feng, Yue Cao, James M Balter
A technique for generating MRI-derived synthetic CT volumes (MRCTs) is demonstrated in support of adaptive liver stereotactic body radiation therapy (SBRT). Under IRB approval, 16 subjects with hepatocellular carcinoma were scanned using a single MR pulse sequence (T1 Dixon). Air-containing voxels were identified by intensity thresholding on T1-weighted, water and fat images. The envelope of the anterior vertebral bodies was segmented from the fat image and fuzzy-C-means (FCM) was used to classify each non-air voxel as mid-density, lower-density, bone, or marrow in the abdomen, with only bone and marrow classified within the vertebral body envelope...
April 21, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28297355/mr-image-based-synthetic-ct-for-imrt-prostate-treatment-planning-and-cbct-image-guided-localization
#15
Shupeng Chen, Hong Quan, An Qin, Seonghwan Yee, Di Yan
The purpose of this study was to propose and evaluate a method of creating a synthetic CT (S-CT) from MRI simulation for dose calculation and daily CBCT localization. A pair of MR and CT images was obtained in the same day from each of 10 prostate patients. The pair of MR and CT images was preregistered using the deformable image registration (DIR). Using the corresponding displacement vector field (atlas-DVF), the CT image was deformed to the MR image to create an atlas MR-CT pair. Regions of interest (ROI) on the atlas MR-CT pair were delineated and used to create atlas-ROI masks...
May 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28269719/3d-small-structure-detection-in-medical-image-using-texture-analysis
#16
Fei Gao, Min Zhang, Teresa Wu, Kevin M Bennett
Small structure segmentation from medical images is a challenging problem yet has important applications. Examples are labeling cell, lesion and glomeruli for disease diagnosis, just to name a few. Though extensive research has proposed various detectors for this type of problem, most are 2D detectors. Recently, we have developed a Hessian based 3D detector to segment small structures from medical images (e.g., MRI). In our detector, two 3D geometrical features: regional blobness and flatness, in conjunction with the intensity features are fully utilized to serve the segmentation purpose...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268368/sampling-and-recovery-of-mri-data-using-low-rank-tensor-models
#17
Daniel Banco, Shuchin Aeron, W Scott Hoge
In this paper we investigate the utility of several low-rank models for recovery of Magnetic Resonance Imaging (MRI) data from limited sampling in the k - t space for dynamic imaging. In particular, for 3D temporal (2D space + time) MRI data we employ several tensor factorization techniques and assess the degree of dimensionality reduction, or compressibility, that can be obtained. This algebraic approach is more data adaptive, in contrast to existing compressed sensing (CS) based methods that exploit sparsity in a transform domain, such as wavelets or total variation...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28267626/bayesian-switching-factor-analysis-for-estimating-time-varying-functional-connectivity-in-fmri
#18
Jalil Taghia, Srikanth Ryali, Tianwen Chen, Kaustubh Supekar, Weidong Cai, Vinod Menon
There is growing interest in understanding the dynamical properties of functional interactions between distributed brain regions. However, robust estimation of temporal dynamics from functional magnetic resonance imaging (fMRI) data remains challenging due to limitations in extant multivariate methods for modeling time-varying functional interactions between multiple brain areas. Here, we develop a Bayesian generative model for fMRI time-series within the framework of hidden Markov models (HMMs). The model is a dynamic variant of the static factor analysis model (Ghahramani and Beal, 2000)...
March 3, 2017: NeuroImage
https://www.readbyqxmd.com/read/28257339/symri-of-the-brain-rapid-quantification-of-relaxation-rates-and-proton-density-with-synthetic-mri-automatic-brain-segmentation-and-myelin-measurement
#19
Akifumi Hagiwara, Marcel Warntjes, Masaaki Hori, Christina Andica, Misaki Nakazawa, Kanako Kunishima Kumamaru, Osamu Abe, Shigeki Aoki
Conventional magnetic resonance images are usually evaluated using the image signal contrast between tissues and not based on their absolute signal intensities. Quantification of tissue parameters, such as relaxation rates and proton density, would provide an absolute scale; however, these methods have mainly been performed in a research setting. The development of rapid quantification, with scan times in the order of 6 minutes for full head coverage, has provided the prerequisites for clinical use. The aim of this review article was to introduce a specific quantification method and synthesis of contrast-weighted images based on the acquired absolute values, and to present automatic segmentation of brain tissues and measurement of myelin based on the quantitative values, along with application of these techniques to various brain diseases...
March 3, 2017: Investigative Radiology
https://www.readbyqxmd.com/read/28242137/evaluation-of-a-multi-atlas-ct-synthesis-approach-for-mri-only-radiotherapy-treatment-planning
#20
F Guerreiro, N Burgos, A Dunlop, K Wong, I Petkar, C Nutting, K Harrington, S Bhide, K Newbold, D Dearnaley, N M deSouza, V A Morgan, J McClelland, S Nill, M J Cardoso, S Ourselin, U Oelfke, A C Knopf
BACKGROUND AND PURPOSE: Computed tomography (CT) imaging is the current gold standard for radiotherapy treatment planning (RTP). The establishment of a magnetic resonance imaging (MRI) only RTP workflow requires the generation of a synthetic CT (sCT) for dose calculation. This study evaluates the feasibility of using a multi-atlas sCT synthesis approach (sCTa) for head and neck and prostate patients. MATERIAL AND METHODS: The multi-atlas method was based on pairs of non-rigidly aligned MR and CT images...
March 2017: Physica Medica: PM
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