keyword
MENU ▼
Read by QxMD icon Read
search

high MRI

keyword
https://www.readbyqxmd.com/read/27915429/high-risk-pml-patients-switching-from-natalizumab-to-alemtuzumab-an-observational-study
#1
Simona Malucchi, Marco Capobianco, Marianna Lo Re, Maria Malentacchi, Alessia di Sapio, Manuela Matta, Francesca Sperli, Antonio Bertolotto
INTRODUCTION: The choice of therapy in patients withdrawing from natalizumab treatment is still an open question and neurologists need strategies to manage this group of patients. The aim of this study is to evaluate if alemtuzumab is able to control the disease when used in patient who have stopped natalizumab. METHODS: 16 patients stopped natalizumab treatment after a median number of 20 infusions (range 12-114); all the patients were responders to natalizumab (neither clinical nor radiological activity during natalizumab therapy) and the reason for stopping was the risk of PML for all of them...
December 3, 2016: Neurology and Therapy
https://www.readbyqxmd.com/read/27915120/gradient-and-shim-technologies-for-ultra-high-field-mri
#2
Simone A Winkler, Franz Schmitt, Hermann Landes, Josh DeBever, Trevor Wade, Andrew Alejski, Brian K Rutt
Ultra High Field (UHF) MRI requires improved gradient and shim performance to fully realize the promised gains (SNR as well as spatial, spectral, diffusion resolution) that higher main magnetic fields offer. Both the more challenging UHF environment by itself, as well as the higher currents used in high performance coils, require a deeper understanding combined with sophisticated engineering modeling and construction, to optimize gradient and shim hardware for safe operation and for highest image quality. This review summarizes the basics of gradient and shim technologies, and outlines a number of UHF-related challenges and solutions...
November 30, 2016: NeuroImage
https://www.readbyqxmd.com/read/27915115/a-novel-measure-of-reliability-in-diffusion-tensor-imaging-after-data-rejections-due-to-subject-motion
#3
V Sairanen, L Kuusela, O Sipilä, S Savolainen, S Vanhatalo
Diffusion Tensor Imaging (DTI) is commonly challenged by subject motion during data acquisition, which often leads to corrupted image data. Currently used procedure in DTI analysis is to correct or completely reject such data before tensor estimations, however assessing the reliability and accuracy of the estimated tensor in such situations has evaded previous studies. This work aims to define the loss of data accuracy with increasing image rejections, and to define a robust method for assessing reliability of the result at voxel level...
November 30, 2016: NeuroImage
https://www.readbyqxmd.com/read/27914911/cervical-cancer-brachytherapy-in-canada-a-focus-on-interstitial-brachytherapy-utilization
#4
Amandeep S Taggar, Tien Phan, Laurel Traptow, Robyn Banerjee, Corinne M Doll
PURPOSE: Brachytherapy (BT) techniques for cervical cancer in Canada have changed over the last decade, with evolution to high-dose-rate and image-guided BT. However, there are currently no national data on the use of interstitial BT (IBT). The purpose of this study was to document IBT utilization in Canadian centers, as well as update details of cervical cancer BT practices. METHODS AND MATERIALS: All Canadian centers with gynecologic BT services (n = 33) were identified, and one gynecology radiation oncologist per center was sent a 33-item e-mail questionnaire regarding their center's practice for cervical cancer BT in 2015...
November 30, 2016: Brachytherapy
https://www.readbyqxmd.com/read/27914180/burned-out-testis-tumors-in-asymptomatic-infertile-men-multiparametric-sonography-and-mri-findings
#5
Laurence Rocher, Ludivine Glas, Marie France Bellin, Sophie Ferlicot, Vincent Izard, Gerard Benoit, Laurence Albiges, Karim Fizazi, Jean-Michel Correas
Multiparametric testicular ultrasound and magnetic resonance imaging (MRI) findings were analyzed in a series of 10 infertile asymptomatic men presenting with pathologically confirmed burned-out testicular tumors. Color/power Doppler ultrasound (CDUS), shear wave elastography (SWE), contrast-enhanced ultrasonography (CEUS), and MRI were performed on 10, 5, 6, and 7 patients, respectively. All lesions appeared as a hypoechoic and hypovascular nodular area at CDUS, SWE, CEUS CDUS, and CEUS (if performed). Shear wave elastography showed a stiffer nodular area compared with the surrounding/contralateral tissues (13 versus 2 kPa); MRI revealed a well-delineated nodular area in hypointense signal on T2, a high apparent diffusion coefficient value, and a lack of enhancement...
December 3, 2016: Journal of Ultrasound in Medicine: Official Journal of the American Institute of Ultrasound in Medicine
https://www.readbyqxmd.com/read/27913827/intra-lesional-spatial-correlation-of-static-and-dynamic-fet-pet-parameters-with-mri-based-cerebral-blood-volume-in-patients-with-untreated-glioma
#6
Jens Göttler, Mathias Lukas, Anne Kluge, Stephan Kaczmarz, Jens Gempt, Florian Ringel, Mona Mustafa, Bernhard Meyer, Claus Zimmer, Markus Schwaiger, Stefan Förster, Christine Preibisch, Thomas Pyka
PURPOSE: (18)F-fluorethyltyrosine-(FET)-PET and MRI-based relative cerebral blood volume (rCBV) have both been used to characterize gliomas. Recently, inter-individual correlations between peak static FET-uptake and rCBV have been reported. Herein, we assess the local intra-lesional relation between FET-PET parameters and rCBV. METHODS: Thirty untreated glioma patients (27 high-grade) underwent simultaneous PET/MRI on a 3 T hybrid scanner obtaining structural and dynamic susceptibility contrast sequences...
December 2, 2016: European Journal of Nuclear Medicine and Molecular Imaging
https://www.readbyqxmd.com/read/27913338/intracardiac-vortex-dynamics-by-high-frame-rate-doppler-vortography-i-in-vivo-i-comparison-with-vector-flow-mapping-and-4-d-flow-mri
#7
Julia Faurie, Mathilde Baudet, Kondo Claude Assi, Dominique Auger, Guillaume Gilbert, Francois Tournoux, Damien Garcia
Recent studies have suggested that intracardiac vortex flow imaging could be of clinical interest to early diagnose the diastolic heart function. Doppler vortography has been intro-duced as a simple color Doppler method to detect and quantify intraventricular vortices. This method is able to locate a vortex core based on the recognition of an antisymmetric pattern in the Doppler velocity field. Because the heart is a fast-moving organ, high frame rates are needed to decipher the whole blood vortex dynamics during diastole...
November 29, 2016: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/27913180/structure-activity-and-in-vivo-evaluation-of-a-novel-lipoprotein-lipase-lpl-activator
#8
Werner J Geldenhuys, Joel Caporoso, Thomas C Leeper, Yoon-Kwang Lee, Li Lin, Altaf S Darvesh, Prabodh Sadana
Elevated triglycerides (TG) contribute towards increased risk for cardiovascular disease. Lipoprotein lipase (LPL) is an enzyme that is responsible for the metabolism of core triglycerides of very-low density lipoproteins (VLDL) and chylomicrons in the vasculature. In this study, we explored the structure-activity relationships of our lead compound (C10d) that we have previously identified as an LPL agonist. We found that the cyclopropyl moiety of C10d is not absolutely necessary for LPL activity. Several substitutions were found to result in loss of LPL activity...
November 21, 2016: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/27911950/a-specialized-multi-transmit-head-coil-for-high-resolution-fmri-of-the-human-visual-cortex-at-7t
#9
Shubharthi Sengupta, Alard Roebroeck, Valentin G Kemper, Benedikt A Poser, Jan Zimmermann, Rainer Goebel, Gregor Adriany
PURPOSE: To design, construct and validate radiofrequency (RF) transmit and receive phased array coils for high-resolution visual cortex imaging at 7 Tesla. METHODS: A 4 channel transmit and 16 channel receive array was constructed on a conformal polycarbonate former. Transmit field efficiency and homogeneity were simulated and validated, along with the Specific Absorption Rate, using [Formula: see text] mapping techniques and electromagnetic simulations. Receiver signal-to-noise ratio (SNR), temporal SNR (tSNR) across EPI time series, g-factors for accelerated imaging and noise correlations were evaluated and compared with a commercial 32 channel whole head coil...
2016: PloS One
https://www.readbyqxmd.com/read/27911313/challenges-in-screening-and-recruitment-for-a-neuroimaging-study-in-cognitively-impaired-geriatric-inpatients
#10
Ivayla Apostolova, Catharina Lange, Anna Roberts, Hans Joachim Igel, Anja Mäurer, Stephanie Liese, Melanie Estrella, Vikas Prasad, Elisabeth Stechl, Gernot Lämmler, Elisabeth Steinhagen-Thiessen, Ralph Buchert
BACKGROUND: Neuroimaging-based biomarkers have the potential to improve etiological diagnosis of cognitive impairment in elderly inpatients. However, there is a relative lack of studies on neuroimaging-based biomarkers in hospitalized geriatric patients, as the vast majority of neuroimaging studies in dementia have focused on memory clinic outpatients. An important aspect of study planning is a priori estimation of the rate of screen failures. OBJECTIVE: To report on the rate and causes of screen failures in a prospective study on the utility of neuroimaging (PET, MRI) for the etiological diagnosis of newly manifested cognitive impairment in acutely hospitalized geriatric patients...
November 28, 2016: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/27911308/the-effects-of-gene-mutations-on%C3%A2-default%C3%A2-mode-network-in%C3%A2-familial%C3%A2-alzheimer-s-disease
#11
Xiaozhen Li, Eric Westman, Steinunn Thordardottir, Anne Kinhult Ståhlbom, Ove Almkvist, Kaj Blennow, Lars-Olof Wahlund, Caroline Graff
Familial Alzheimer's disease (FAD) mutations have very high penetrance but age at onset and rate of disease progression differ. Neuroimaging and cerebrospinal fluid (CSF) examinations in mutation carriers (MCs) may provide an opportunity to identify early biomarkers that can be used to track disease progression from presymptomatic to the dementia stages of disease. The default mode network (DMN) is a resting state neuronal network composed of regions known to associate with amyloid deposition in AD. We hypothesized that functional connectivity in the DMN might change at pre-clinical stages in FAD MCs and correlate with changes in CSF biomarkers as a consequence of AD brain pathology...
November 29, 2016: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/27911301/tau-platelets-correlate-with-regional-brain%C3%A2-atrophy-in-patients-with-alzheimer-s%C3%A2-disease
#12
Andrea Slachevsky, Leonardo Guzmán-Martínez, Carolina Delgado, Pablo Reyes, Gonzalo A Farías, Carlos Muñoz-Neira, Eduardo Bravo, Mauricio Farías, Patricia Flores, Cristian Garrido, James T Becker, Oscar L López, Ricardo B Maccioni
BACKGROUND: Intracellular neurofibrillary tangles are part of the core pathology of Alzheimer's disease (AD), which are mainly composed of hyperphosphorylated tau protein. OBJECTIVES: The purpose of this study is to determine whether high molecular weight (HMW) or low molecular weight (LMW) tau protein levels, as well as the ratio HMW/LMW, present in platelets correlates with brain magnetic resonance imaging (MRI) structural changes in normal and cognitively impaired subjects...
November 26, 2016: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/27911291/a-metal-free-method-for-producing-mri-contrast-at-amyloid-%C3%AE
#13
Silvia Hilt, Tang Tang, Jeffrey H Walton, Madhu Budamagunta, Izumi Maezawa, Tamás Kálai, Kálmán Hideg, Vikrant Singh, Heike Wulff, Qizhi Gong, Lee-Way Jin, Angelique Louie, John C Voss
Alzheimer's disease (AD) is characterized by depositions of the amyloid-β (Aβ) peptide in the brain. The disease process develops over decades, with substantial neurological loss occurring before a clinical diagnosis of dementia can be rendered. It is therefore imperative to develop methods that permit early detection and monitoring of disease progression. In addition, the multifactorial pathogenesis of AD has identified several potential avenues for AD intervention. Thus, evaluation of therapeutic candidates over lengthy trial periods also demands a practical, noninvasive method for measuring Aβ in the brain...
November 26, 2016: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/27911245/use-of-magnetic-resonance-imaging-to-detect-occult-spinal-dysraphism-in-infants
#14
Brent R O'Neill, Danielle Gallegos, Alex Herron, Claire Palmer, Nicholas V Stence, Todd C Hankinson, C Corbett Wilkinson, Michael H Handler
OBJECTIVE Cutaneous stigmata or congenital anomalies often prompt screening for occult spinal dysraphism (OSD) in asymptomatic infants. While a number of studies have examined the results of ultrasonography (US) screening, less is known about the findings when MRI is used as the primary imaging modality. The object of this study was to assess the results of MRI screening for OSD in infants. METHODS The authors undertook a retrospective review of all infants who had undergone MRI of the lumbar spine to screen for OSD over a 6-year period (September 2006-September 2012)...
December 2, 2016: Journal of Neurosurgery. Pediatrics
https://www.readbyqxmd.com/read/27910827/an-improved-asymmetric-gradient-coil-design-for-high-resolution-mri-head-imaging
#15
Fangfang Tang, Feng Liu, Fabio Freschi, Yu Li, Maurizio Repetto, Luca Giaccone, Yaohui Wang, Stuart Crozier
For head magnetic resonance imaging, local gradient coils are often used to achieve high solution images. To accommodate the human head and shoulder, the head gradient coils are usually designed in an asymmetric configuration, allowing the region-of-uniformity (ROU) close to the coil's patient end. However, the asymmetric configuration leads to technical difficulties in maintaining a high gradient performance for the insertable head coil with very limited space. In this work, we present a practical design configuration of an asymmetric insertable gradient head coil offering an improved performance...
December 21, 2016: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/27910089/bilateral-endolymphatic-hydrops-in-a-patient-with-migraine-variant-without-vertigo-a-case-report
#16
Isabelle Y Liu, Akira Ishiyama, Ali R Sepahdari, Kevin Johnson, Gail Ishiyama
OBJECTIVE: To use modern high-resolution inner ear imaging modalities to evaluate for endolymphatic hydrops (EH) in a patient with migraine-associated fluctuating hearing loss without vertigo spells or dizziness. BACKGROUND: EH has been well described in patients with Meniere's disease on both human temporal bone studies and modern high-resolution imaging; however, there is no study to date, to our knowledge, that examines the presence of EH in a patient with migraine and bilateral hearing loss...
December 2, 2016: Headache
https://www.readbyqxmd.com/read/27909651/hybrid-decompression-and-fixation-technique-for-the-treatment-of-multisegmental-cervical-spondylotic-myelopathy
#17
Barón Zárate-Kalfopulos, Walter Araos-Silva, Alejandro Reyes-Sánchez, Luis Miguel Rosales-Olivarez, Armando Alpizar-Aguirre, Francisco Lopez Melendez
BACKGROUND: Cervical spondilotic myelopathy (CSM) is defined as the compromise of the spinal cord due to degenerative changes of the cervical spine. It is the most common cause of spinal cord dysfunction in patients over 55 years. An early surgical management it is paramount to achieve better neurological outcome. There is still controversy regarding the appropriate surgical treatment for multisegmental CSM involving three or more levels. The hybrid decompression and fixation technique combines one or two level corpectomy and a single level discectomy in order to obtain optimum decompression and fixation in patients with multilevel cervical myelopathy...
2016: International Journal of Spine Surgery
https://www.readbyqxmd.com/read/27908678/avoidance-of-late-rectal-toxicity-after-high-dose-rate-brachytherapy-boost-treatment-for-prostate-cancer
#18
Borut Kragelj, Jernej Zlatic, Lijana Zaletel-Kragelj
PURPOSE: To elucidate potential risk factors important for the appearance of late rectal toxicity (LRT) after high-dose-rate boost treatment (HDRBT) of prostate cancer and to validate the predictive value of the minimal dose to the most exposed 2 cc of rectum received with HDRBT (D2ccrect). METHODS AND MATERIALS: The study of LRT, defined as relative deterioration of defecation problems (RDDP) (stool frequency, pain, rectal bleeding, fecal urgency, and incontinence) during follow-up period, was carried out on 88 patients, consecutively treated from October 2006 through April 2011 with HDRBT of 3 × 6-7 Gy to 50-50...
November 28, 2016: Brachytherapy
https://www.readbyqxmd.com/read/27908188/polymer-gel-dosimetry-for-measuring-the-dose-near-thin-high-z-materials-irradiated-with-high-energy-photon-beams
#19
Leighton L Warmington, N Gopishankar, John H Broadhurst, Yoichi Watanabe
PURPOSE: To investigate the feasibility of three-dimensional (3D) dose measurements near thin high-Z materials placed in a water-like medium by using a polymer gel dosimeter (PGD) when the medium was irradiated with high energy photon beams. METHODS: PGD is potentially a useful tool for this application because it can record the dose around a small object made of a high-Z material in a continuous 3D medium. In this study, the authors manufactured a methacrylic acid-based normoxic PGD, nMAG...
December 2016: Medical Physics
https://www.readbyqxmd.com/read/27908177/automatic-segmentation-of-right-ventricle-in-cardiac-cine-mr-images-using-a-saliency-analysis
#20
Angélica Atehortúa, Maria A Zuluaga, Juan D García, Eduardo Romero
PURPOSE: Accurate measurement of the right ventricle (RV) volume is important for the assessment of the ventricular function and a biomarker of the progression of any cardiovascular disease. However, the high RV variability makes difficult a proper delineation of the myocardium wall. This paper introduces a new automatic method for segmenting the RV volume from short axis cardiac magnetic resonance (MR) images by a salient analysis of temporal and spatial observations. METHODS: The RV volume estimation starts by localizing the heart as the region with the most coherent motion during the cardiac cycle...
December 2016: Medical Physics
keyword
keyword
96045
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"