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https://www.readbyqxmd.com/read/28900819/a-homozygous-pigo-mutation-associated-with-severe-infantile-epileptic-encephalopathy-and-corpus-callosum-hypoplasia-but-normal-alkaline-phosphatase-levels
#1
Yoav Zehavi, Anja von Renesse, Etty Daniel-Spiegel, Yonatan Sapir, Luci Zalman, Ilana Chervinsky, Markus Schuelke, Rachel Straussberg, Ronen Spiegel
We describe two sisters from a consanguineous Arab family with global developmental delay, dystrophy, axial hypotonia, epileptic encephalopathy dominated by intractable complex partial seizures that were resistant to various anti-epileptic treatments. Dysmorphic features comprised low set ears, hypertelorism, upslanting palpebral fissures, a broad nasal bridge, and blue sclera with elongated eyelashes. Brain MRI in both children showed a corpus callosum hypoplasia that was evident already in utero and evolving cortical atrophy...
September 13, 2017: Metabolic Brain Disease
https://www.readbyqxmd.com/read/28885152/multimodal-breast-parenchymal-patterns-correlation-using-a-patient-specific-biomechanical-model
#2
Eloy Garcia, Yago Diez, Oliver Diaz, Xavier Llado, Albert Gubern-Merida, Robert Marti, Joan Marti, Arnau Oliver
In this paper we aim to produce a realistic 2D projection of the breast parenchymal distribution from a 3D breast magnetic resonance image (MRI). To evaluate the accuracy of our simulation, we compare our results with the local breast density (i.e. density map) obtained from the complementary fullfield digital mammogram. To achieve this goal, we have developed a fully automatic framework which registers MRI volumes to X-ray mammograms using a subject-specific biomechanical model of the breast. The optimization step modifies the position, orientation and elastic parameters of the breast model to perform the alignment between the images...
September 7, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28884520/relative-pressure-estimation-from-velocity-measurements-in-blood-flows-state-of-the-art-and-new-approaches
#3
Cristóbal Bertoglio, Rodolfo Núñez, Felipe Galarce, David Nordsletten, Axel Osses
The relative pressure difference across stenotic blood vessels serves as an important clinical index for the diagnosis of many cardiovascular diseases. While the clinical gold standard for relative pressure difference measurements is invasive catheterization, Phase-Contrast Magnetic Resonance Imaging has emerged as a promising tool for enabling a non-invasive quantification, by linking highly spatially resolved velocity measurements with relative pressures via the incompressible Navier-Stokes equations. In this work we provide a review and analysis of current methods for relative pressure estimation and propose three additional techniques...
September 7, 2017: International Journal for Numerical Methods in Biomedical Engineering
https://www.readbyqxmd.com/read/28880160/pvr-patch-to-volume-reconstruction-for-large-area-motion-correction-of-fetal-mri
#4
Amir Alansary, Martin Rajchl, Steven G McDonagh, Maria Murgasova, Mellisa Damodaram, David F A Lloyd, Alice Davidson, Mary Rutherford, Joseph V Hajnal, Daniel Rueckert, Bernhard Kainz
In this paper we present a novel method for the correction of motion artifacts that are present in fetal Magnetic Resonance Imaging (MRI) scans of the whole uterus. Contrary to current slice-to-volume registration (SVR) methods, requiring an inflexible anatomical enclosure of a single investigated organ, the proposed patch-to-volume reconstruction (PVR) approach is able to reconstruct a large field of view of non-rigidly deforming structures. It relaxes rigid motion assumptions by introducing a specific amount of redundant information that is exploited with parallelized patch-wise optimization, super-resolution, and automatic outlier rejection...
September 1, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28867378/autologous-fat-transplants-to-deliver-glitazone-and-adiponectin-for-vasculoprotection
#5
William G Sanders, Huan Li, Ilya Zhuplatov, Yuxia He, Seong-Eun Kim, Alfred K Cheung, Jayant Agarwal, Christi M Terry
The insulin sensitizing glitazone drugs, rosiglitazone (ROS) and pioglitazone (PGZ) both have anti-proliferative and anti-inflammatory effects and induce adipose tissue (fat) to produce the vaso-protective protein adiponectin. Stenosis due to intimal hyperplasia development often occurs after placement of arteriovenous synthetic grafts used for hemodialysis. This work was performed to characterize the in vitro and in vivo effects of ROS or PGZ incorporation in fat and to determine if fat/PGZ depots could decrease vascular hyperplasia development in a porcine model of hemodialysis arteriovenous graft stenosis...
September 1, 2017: Journal of Controlled Release: Official Journal of the Controlled Release Society
https://www.readbyqxmd.com/read/28862360/mechanically-stimulated-biomarkers-signal-cartilage-changes-over-5-years-consistent-with-disease-progression-in-medial-knee-osteoarthritis-patients
#6
Constance R Chu, Shikha Sheth, Jennifer C Erhart-Hledik, Bao Do, Matthew R Titchenal, Thomas P Andriacchi
Using serum biomarkers to assess osteoarthritis (OA) disease state and risks of progression remain challenging. This study tested the hypothesis that changes to serum biomarkers in response to a mechanical stimulus in patients with medial knee OA signal cartilage thickness changes five years later. Specifically, serum concentrations of a collagen degradation marker (C1,2C) and a chondroitin sulfate synthesis marker (CS846) were measured 0.5 and 5.5 hours after a 30-minute walk in 16 patients. Regional cartilage thickness changes measured from magnetic resonance images obtained at study entry and at 5-year follow-up were tested for correlations with baseline biomarker changes after mechanical stimulus, and for differences between groups stratified based on whether biomarker levels increased or decreased...
September 1, 2017: Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society
https://www.readbyqxmd.com/read/28860625/detection-of-dynamic-substrate-binding-using-mri
#7
Nirbhay N Yadav, Xing Yang, Yuguo Li, Wenbo Li, Guanshu Liu, Peter C M van Zijl
Magnetic Resonance Imaging (MRI) is rarely used for molecular binding studies and never without synthetic metallic labels. We designed an MRI approach that can specifically detect the binding of natural substrates (i.e. no chemical labels). To accomplish such detection of substrate-target interaction only, we exploit (i) the narrow resonance of aliphatic protons in free substrate for selective radio-frequency (RF) labeling and, (ii) the process of immobilisation upon binding to a solid-like target for fast magnetic transfer of this label over protons in the target backbone...
August 31, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28843375/mr-opera-a-multicenter-multivendor-validation-of-magnetic-resonance-imaging-only-prostate-treatment-planning-using-synthetic-computed-tomography-images
#8
Emilia Persson, Christian Gustafsson, Fredrik Nordström, Maja Sohlin, Adalsteinn Gunnlaugsson, Karin Petruson, Niina Rintelä, Kristoffer Hed, Lennart Blomqvist, Björn Zackrisson, Tufve Nyholm, Lars E Olsson, Carl Siversson, Joakim Jonsson
PURPOSE: To validate the dosimetric accuracy and clinical robustness of a commercially available software for magnetic resonance (MR) to synthetic computed tomography (sCT) conversion, in an MR imaging-only workflow for 170 prostate cancer patients. METHODS AND MATERIALS: The 4 participating centers had MriPlanner (Spectronic Medical), an atlas-based sCT generation software, installed as a cloud-based service. A T2-weighted MR sequence, covering the body contour, was added to the clinical protocol...
June 16, 2017: International Journal of Radiation Oncology, Biology, Physics
https://www.readbyqxmd.com/read/28838117/technique-for-mini-open-decompression-of-chiari-type-i-malformation-in-adults
#9
Peyman Pakzaban
BACKGROUND: The technique for decompression of Chiari type I malformation relies on open exposure of craniocervical junction for suboccipital craniectomy and upper cervical laminectomy with or without duraplasty. There is no detailed technical report of a minimally invasive approach for Chiari decompression in adults. OBJECTIVE: To describe a mini-open technique for decompression of Chiari type I malformation (including duraplasty) in adults. METHODS: Six consecutive adult patients with symptomatic Chiari type I malformation underwent decompression through a 3 to 4 cm midline incision via a speculum retractor...
August 1, 2017: Operative Neurosurgery (Hagerstown, Md.)
https://www.readbyqxmd.com/read/28828228/the-impact-of-hemodynamic-variability-and-signal-mixing-on-the-identifiability-of-effective-connectivity-structures-in-bold-fmri
#10
Natalia Z Bielczyk, Alberto Llera, Jan K Buitelaar, Jeffrey C Glennon, Christian F Beckmann
PURPOSE: Multiple computational studies have demonstrated that essentially all current analytical approaches to determine effective connectivity perform poorly when applied to synthetic functional Magnetic Resonance Imaging (fMRI) datasets. In this study, we take a theoretical approach to investigate the potential factors facilitating and hindering effective connectivity research in fMRI. MATERIALS AND METHODS: In this work, we perform a simulation study with use of Dynamic Causal Modeling generative model in order to gain new insights on the influence of factors such as the slow hemodynamic response, mixed signals in the network and short time series, on the effective connectivity estimation in fMRI studies...
August 2017: Brain and Behavior
https://www.readbyqxmd.com/read/28816657/a-dynamic-regression-approach-for-frequency-domain-partial-coherence-and-causality-analysis-of-functional-brain-networks
#11
Lipeng Ning, Yogesh Rathi
Coherence and causality measures are often used to analyze the influence of one region on another during analysis of functional brain networks. The analysis methods usually involve a regression problem where the signal of interest is decomposed into a mixture of regressor and a residual signal. In this paper, we revisit this basic problem and present solutions that provide the minimal-entropy residuals for different types of regression filters, such as causal, instantaneously causal and noncausal filters. Using optimal prediction theory, we derive several novel frequency-domain expressions for partial coherence, causality and conditional causality analysis...
August 14, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28812358/bioinspired-active-stealth-magneto-nanomicelles-for-theranostics-combining-efficient-mri-and-enhanced-drug-delivery
#12
Kai-Long Zhang, Jie Zhou, Hong Zhou, Ying Wu, Rui Liu, Li-Li Wang, Wei-Wen Lin, Guoming Huang, Huang-Hao Yang
The mononuclear phagocyte system (MPS) with key roles in recognition and clearance of foreign particles, is a major constraint to nanoparticle-based delivery systems. The desire to improve the delivery efficiency has prompted the search for stealthy long-circulating nanoplatforms. Herein, we design an antiphagocytic delivery system with "active" stealth behavior for cancer theranostics combining efficient MRI and enhanced drug delivery. We modify self-peptide, a synthetic peptide for active immunomodulation, to biodegradable poly(lactide-glycolide)-poly(ethylene glycol) (PLGA-PEG), then utilize the self-assembly properties of PLGA-PEG to form nanomicelles that encapsulating iron oxide (IO) nanoparticles and anticancer drug paclitaxel (PTX)...
September 13, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28809668/tractography-based-score-for-learning-effective-connectivity-from-multimodal-imaging-data-using-dynamic-bayesian-networks
#13
Shilpa Dang, Santanu Chaudhury, Brejesh Lall, Prasun K Roy
OBJECTIVE: Effective connectivity (EC) is the methodology for determining functional-integration among the functionally-active segregated regions of the brain. By definition [1] EC is "the causal influence exerted by one neuronal group on another" which is constrained by anatomical connectivity (AC) (axonal connections). AC is necessary for EC but does not fully determine it, because synaptic communication occurs dynamically in a context-dependent fashion. Although there is a vast emerging evidence of structure-function relationship using multimodal imaging studies, till date only a few studies have done joint modelling of the two modalities: functional MRI (fMRI) and Diffusion Tensor Imaging (DTI)...
August 10, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28803112/in-vivo-documentation-of-shape-and-position-changes-of-mri-visible-mesh-placed-in-rectovaginal-septum
#14
Iva Urbankova, Nikhil Sindhwani, Geertje Callewaert, Alice Turri, Rita Rinkijevic, Lucie Hympanova, Andrew Feola, Jan Deprest
BACKGROUND AND OBJECTIVE: Large deformations in synthetic meshes used in pelvic organ prolapse surgery may lead to suboptimal support for the underlying tissue, graft-related complications as well as recurrence. Our aim was to quantify in vivo longitudinal changes in mesh shape and geometry in a large animal model. We compare two commonly used mesh shapes, armed and flat, that are differently affixed. The secondary outcomes were active and passive biomechanical properties. METHODS: A total of 18 animals were used...
August 5, 2017: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/28789598/development-of-a-computerized-4-d-mri-phantom-for-liver-motion-study
#15
Chunhao Wang, Fang-Fang Yin, W P Segars, Zheng Chang, Lei Ren
PURPOSE: To develop a 4-dimensional computerized magnetic resonance imaging phantom with image textures extracted from real patient scans for liver motion studies. METHODS: The proposed phantom was developed based on the current version of 4-dimensional extended cardiac-torso computerized phantom and a clinical magnetic resonance scan. Initially, the extended cardiac-torso phantom was voxelized in abdominal-chest region at the end of exhalation phase. Structures/tissues were classified into 4 categories: (1) Seven key textured organs, including liver, gallbladder, spleen, stomach, heart, kidneys, and pancreas, were mapped from a clinical T1-weighted liver magnetic resonance scan using deformable registration...
January 1, 2017: Technology in Cancer Research & Treatment
https://www.readbyqxmd.com/read/28781414/test-suite-for-image-based-motion-estimation-of-the-brain-and-tongue
#16
Jordan Ramsey, Jerry L Prince, Arnold D Gomez
Noninvasive analysis of motion has important uses as qualitative markers for organ function and to validate biomechanical computer simulations relative to experimental observations. Tagged MRI is considered the gold standard for noninvasive tissue motion estimation in the heart, and this has inspired multiple studies focusing on other organs, including the brain under mild acceleration and the tongue during speech. As with other motion estimation approaches, using tagged MRI to measure 3D motion includes several preprocessing steps that affect the quality and accuracy of estimation...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28777721/infinite-von-mises-fisher-mixture-modeling-of-whole-brain-fmri-data
#17
Rasmus E Røge, Kristoffer H Madsen, Mikkel N Schmidt, Morten Mørup
Cluster analysis of functional magnetic resonance imaging (fMRI) data is often performed using gaussian mixture models, but when the time series are standardized such that the data reside on a hypersphere, this modeling assumption is questionable. The consequences of ignoring the underlying spherical manifold are rarely analyzed, in part due to the computational challenges imposed by directional statistics. In this letter, we discuss a Bayesian von Mises-Fisher (vMF) mixture model for data on the unit hypersphere and present an efficient inference procedure based on collapsed Markov chain Monte Carlo sampling...
October 2017: Neural Computation
https://www.readbyqxmd.com/read/28735215/estimation-of-individual-axon-bundle-properties-by-a-multi-resolution-discrete-search-method
#18
Ricardo Coronado-Leija, Alonso Ramirez-Manzanares, Jose Luis Marroquin
A stable, accurate and robust-to-noise method for the estimation of the intra-voxel bundle-wise diffusion properties for diffusion-weighted magnetic resonance imaging is presented. The proposed method overcomes some of the limitations of most of the multi-fiber algorithms in the literature and extends them to estimate the diffusion profiles, improving the estimation of the intra-voxel geometry at challenging microstructure configurations, that is to say: relatively small crossing angles, different voxel-wise anisotropic diffusion profiles and low SNR...
June 29, 2017: Medical Image Analysis
https://www.readbyqxmd.com/read/28725549/performance-of-unscented-kalman-filter-tractography-in-edema-analysis-of-the-two-tensor-model
#19
Ruizhi Liao, Lipeng Ning, Zhenrui Chen, Laura Rigolo, Shun Gong, Ofer Pasternak, Alexandra J Golby, Yogesh Rathi, Lauren J O'Donnell
Diffusion MRI tractography is increasingly used in pre-operative neurosurgical planning to visualize critical fiber tracts. However, a major challenge for conventional tractography, especially in patients with brain tumors, is tracing fiber tracts that are affected by vasogenic edema, which increases water content in the tissue and lowers diffusion anisotropy. One strategy for improving fiber tracking is to use a tractography method that is more sensitive than the traditional single-tensor streamline tractography...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28719864/in-vivo-magnetic-resonance-imaging-of-pancreatic-tumors-using-iron-oxide-nanoworms-targeted-with-ptr86-peptide
#20
Yasaman Ahmadi, Genady Kostenich, Mor Oron-Herman, Wolfgang Wadsak, Markus Mitterhauser, Arie Orenstein, Siroos Mirzaei, Peter Knoll
To cut the high mortality rate of malignant disease such as pancreatic cancer, development of newly diagnostic probes for early stage detection of tumor lesions is required. Multimodal imaging nanoprobes allowing targeted and real time functional/anatomical imaging of tumors meet the demands. For this purpose, a MRI/optical dual-modality probe based on biodegradable magnetic iron oxide nanoworms has been developed. The cross-linked surface of nanoworms were anchored to fluorescent dyes and to FITC.PTR86; a novel synthetic peptide with high affinity towards somatostatin receptors...
July 6, 2017: Colloids and Surfaces. B, Biointerfaces
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