keyword
MENU ▼
Read by QxMD icon Read
search

Echo Planar Imaging

keyword
https://www.readbyqxmd.com/read/27910126/gradient-echo-epi-using-a-high-degree-shim-insert-coil-at-7%C3%A2-t-implications-for-bold-fmri
#1
Tae Kim, Yoojin Lee, Tiejun Zhao, Hoby P Hetherington, Jullie W Pan
PURPOSE: To quantitatively assess the effects of high degree and order (1(st) -4(th+) ) relative to 1(st) -2(nd) degree B0 shimming at 7 Tesla (T) on gradient-echo echo planar imaging (GE-EPI) and blood-oxygen-level dependent (BOLD) activation. METHODS: Simulations and GE-EPI were performed at (2mm)(3) and (3mm)(3) resolution, evaluating the temporal signal-to-noise ratio (tSNR), transverse relaxivity ( R2*), BOLD % signal change and activated pixel counts in a breath-hold task...
December 1, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/27908444/clinical-application-of-apparent-diffusion-coefficient-mapping-in-voxel-based-morphometry-in-the-diagnosis-of-alzheimer-s-disease
#2
H Takahashi, K Ishii, N Kashiwagi, Y Watanabe, H Tanaka, T Murakami, N Tomiyama
AIM: To evaluate the performance of apparent diffusion coefficient (ADC) mapping compared with voxel-based morphometry and to demonstrate the clinical usefulness of ADC mapping in the diagnosis of Alzheimer's disease (AD). MATERIALS AND METHODS: The study population comprised 31 patients with AD (group A) and 24 patients without dementia (group B) who underwent three-dimensional (3D) T1-weighted imaging (WI) and two-dimensional (2D) echo-planar diffusion-weighted imaging (DWI) at 3 T...
November 28, 2016: Clinical Radiology
https://www.readbyqxmd.com/read/27902936/how-restful-is-it-with-all-that-noise-comparison-of-interleaved-silent-steady-state-isss-and-conventional-imaging-in-resting-state-fmri
#3
J Andoh, M Ferreira, I R Leppert, R Matsushita, B Pike, R J Zatorre
Resting-state fMRI studies have become very important in cognitive neuroscience because they are able to identify BOLD fluctuations in brain circuits involved in motor, cognitive, or perceptual processes without the use of an explicit task. Such approaches have been fruitful when applied to various disordered populations, or to children or the elderly. However, insufficient attention has been paid to the consequences of the loud acoustic scanner noise associated with conventional fMRI acquisition, which could be an important confounding factor affecting auditory and/or cognitive networks in resting-state fMRI...
November 27, 2016: NeuroImage
https://www.readbyqxmd.com/read/27902865/small-world-properties-changes-in-mild-traumatic-brain-injury
#4
Yongxia Zhou
PURPOSE: To investigate local and global efficiency changes characterized by small-world properties based on resting-state functional MRI, such as centrality and clustering coefficient, in mild traumatic brain injury (MTBI) patients; and to associate these findings with axonal injury as measured by diffusion tensor imaging (DTI) as well as with post-concussive symptom (PCS). MATERIALS AND METHODS: Thirty patients (mean age 35 ± 13 years) with clinically defined MTBI and 45 age-matched healthy controls (mean age 37 ± 10 years) participated in the experiments...
November 30, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27898201/diffusion-weighted-imaging-of-the-abdomen-impact-of-b-values-on-texture-analysis-features
#5
Anton S Becker, Matthias W Wagner, Moritz C Wurnig, Andreas Boss
The purpose of this work was to systematically assess the impact of the b-value on texture analysis in MR diffusion-weighted imaging (DWI) of the abdomen. In eight healthy male volunteers, echo-planar DWI sequences at 16 b-values ranging between 0 and 1000 s/mm(2) were acquired at 3 T. Three different apparent diffusion coefficient (ADC) maps were computed (0, 750/100, 390, 750 s/mm(2) /all b-values). Texture analysis of rectangular regions of interest in the liver, kidney, spleen, pancreas, paraspinal muscle and subcutaneous fat was performed on DW images and the ADC maps, applying 19 features computed from the histogram, grey-level co-occurrence matrix (GLCM) and grey-level run-length matrix (GLRLM)...
November 29, 2016: NMR in Biomedicine
https://www.readbyqxmd.com/read/27888543/segmented-simultaneous-multi-slice-diffusion-weighted-imaging-with-generalized-trajectories
#6
Michael Herbst, Weiran Deng, Thomas Ernst, V Andrew Stenger
PURPOSE: The purpose of this work is to develop and evaluate a single framework for the use of Cartesian and non-Cartesian segmented trajectories for rapid and robust simultaneous multislice (SMS) diffusion weighted imaging (DWI) at 3 Telsa (T). METHODS: A generalized SMS approach with intrinsic phase navigation using Multiplexed Sensitivity Encoding (MUSE) was developed. Segmented blipped-controlled aliasing in parallel imaging echo planar imaging (EPI) and z-gradient modulated spiral trajectories were examined using SMS DWI scans at 3T with a 32-channel head coil...
November 25, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/27880010/abnormal-baseline-brain-activity-in-parkinson-s-disease-with-and-without-rem-sleep-behavior-disorder-a-resting-state-functional-mri-study
#7
Dan Li, Peiyu Huang, Yufeng Zang, Yuting Lou, Zhidong Cen, Quanquan Gu, Min Xuan, Fei Xie, Zhiyuan Ouyang, Bo Wang, Minming Zhang, Wei Luo
PURPOSE: To investigate the differences in spontaneous brain activity between Parkinson's disease (PD) patients with rapid eye movement sleep behavior disorder (RBD), PD patients without RBD, and normal controls, which may shed new light on the neural mechanism of RBD. MATERIALS AND METHODS: Eighteen PD patients with RBD, 16 patients without RBD, and 19 age- and gender-matched normal controls underwent clinical assessment and functional magnetic resonance imaging (fMRI) with a 3...
November 23, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27858468/a-qualitative-comparison-of-arterial-spin-labelling-and-dynamic-susceptibility-contrast-mri-in-52-children-with-a-range-of-neurological-conditions
#8
Paul A Armitage, Nicholas Skipper, Daniel J A Connolly, Paul D Griffiths
OBJECTIVE: To assess the usefulness of Arterial Spin Labelling (ASL) compared with Dynamic Susceptibility Contrast (DSC) perfusion MRI for typical paediatric neuroimaging applications at 1.5 Tesla. METHODS: 52 children (age: 4 months - 17 years) with a variety of neurological disorders were scanned using 3D ASL and Echo Planar Imaging DSC sequences. All images were reviewed by an experienced neuroradiologist, image quality recorded as 'good', 'acceptable', or 'poor' and diagnostic value noted as being 'greater', 'similar' or 'less' for ASL when compared to DSC...
November 18, 2016: British Journal of Radiology
https://www.readbyqxmd.com/read/27853053/diagnostic-performance-of-diffusion-tensor-imaging-with-readout-segmented-echo-planar-imaging-for-invasive-breast-cancer-correlation-of-adc-and-fa-with-pathological-prognostic-markers
#9
Ken Yamaguchi, Takahiko Nakazono, Ryoko Egashira, Yoshiaki Komori, Jun Nakamura, Tomoyuki Noguchi, Hiroyuki Irie
PURPOSE: To assess the diagnostic performance of readout-segmented echo-planar diffusion tensor imaging (DTI based on rs-EPI) for breast cancer and to determine the correlation between the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values obtained from DTI based on rs-EPI with prognostic markers of invasive breast cancer. MATERIALS AND METHODS: This retrospective study examined 80 pathologically proven breast lesions (22 benign and 58 malignant lesions) of 80 patients who underwent both diffusion-weighted imaging based on single-shot echo-planar imaging (DWI based on ss-EPI) and DTI based on rs-EPI with b-values of 0 and 1000...
November 16, 2016: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/27843735/interhemispheric-difference-images-from-postoperative-diffusion-tensor-imaging-of-gliomas
#10
Robert Kosztyla, Stefan A Reinsberg, Vitali Moiseenko, Brian Toyota, Alan Nichol
Introduction Determining the full extent of gliomas during radiotherapy planning can be challenging with conventional T1 and T2 magnetic resonance imaging (MRI). The purpose of this study was to develop a method to automatically calculate differences in the fractional anisotropy (FA) and mean diffusivity (MD) values in target volumes obtained with diffusion tensor imaging (DTI) by comparing with values from anatomically homologous voxels on the contralateral side of the brain. Methods Seven patients with a histologically confirmed glioma underwent postoperative radiotherapy planning with 1...
October 5, 2016: Curēus
https://www.readbyqxmd.com/read/27836708/the-real-time-fmri-neurofeedback-based-stratification-of-default-network-regulation-neuroimaging-data-repository
#11
Amalia R McDonald, Jordan Muraskin, Nicholas T Van Dam, Caroline Froehlich, Benjamin Puccio, John Pellman, Clemens C C Bauer, Alexis Akeyson, Melissa M Breland, Vince D Calhoun, Steven Carter, Tiffany P Chang, Chelsea Gessner, Alyssa Gianonne, Steven Giavasis, Jamie Glass, Steven Homann, Margaret King, Melissa Kramer, Drew Landis, Alexis Lieval, Jonathan Lisinski, Anna Mackay-Brandt, Brittny Miller, Laura Panek, Hayley Reed, Christine Santiago, Eszter Schoell, Richard Sinnig, Melissa Sital, Elise Taverna, Russell Tobe, Kristin Trautman, Betty Varghese, Lauren Walden, Runtang Wang, Abigail B Waters, Dylan C Wood, F Xavier Castellanos, Bennett Leventhal, Stanley J Colcombe, Stephen LaConte, Michael P Milham, R Cameron Craddock
This data descriptor describes a repository of openly shared data from an experiment to assess inter-individual differences in default mode network (DMN) activity. This repository includes cross-sectional functional magnetic resonance imaging (fMRI) data from the Multi Source Interference Task, to assess DMN deactivation, the Moral Dilemma Task, to assess DMN activation, a resting state fMRI scan, and a DMN neurofeedback paradigm, to assess DMN modulation, along with accompanying behavioral and cognitive measures...
November 9, 2016: NeuroImage
https://www.readbyqxmd.com/read/27828787/speed-in-clinical-magnetic-resonance
#12
Val M Runge, Johannes K Richter, Johannes T Heverhagen
The relevant clinical accelerated magnetic resonance techniques that are available currently for routine patient examinations are reviewed, presenting and discussing the benefits therein when compared with more conventional scans. The focus is on clinical use and practicality, with the review divided into 3 sections. Improvements in 3-dimensional acquisition are first discussed, specifically controlled aliasing in parallel imaging results in higher acceleration, related radial techniques, and CAIPI-Dixon-TWIST-VIBE...
November 8, 2016: Investigative Radiology
https://www.readbyqxmd.com/read/27814138/analysis-of-the-diffusion-tensor-imaging-parameters-of-a-normal-cervical-spinal-cord-in-a-healthy-population
#13
Liang-Feng Wei, Shou-Sen Wang, Zhao-Cong Zheng, Jun Tian, Liang Xue
BACKGROUND: Diffusion tensor imaging (DTI) shows great advantage in the diagnosis of brain diseases, including cervical spinal cord (CSC) disease. This study aims to obtain the normal values of the DTI parameters for a healthy population and to establish a baseline for CSC disease diagnosis using DTI. METHODS: A total of 36 healthy adults were subjected to magnetic resonance imaging (MRI) for the entire CSC using the Siemens 3.0 T MR System. Sagittal DTI acquisition was carried out with a single-shot spin-echo echo-planar imaging (EPI) sequence along 12 non-collinear directions...
November 4, 2016: Journal of Spinal Cord Medicine
https://www.readbyqxmd.com/read/27807795/can-we-shorten-the-q-space-imaging-to-make-it-clinically-feasible
#14
Koji Sakai, Kei Yamada, Kentaro Akazawa, Jun Tazoe, Masashi Yasuike, Hitomi Nagano, Hiroyasu Ikeno, Toshiaki Nakagawa
PURPOSE: Q-space imaging (QSI) is a novel magnetic resonance imaging (MRI) technique that enables assessment of micro-structural changes of white matter. The acquisition time, however, is comparatively long to use for routine clinical assessment. Therefore, the present study investigated the clinically feasible b value combinations to measure the water molecular displacement probability density function (PDF) in healthy subjects. METHODS: The subjects consisted of five healthy volunteers (1 female and 4 male; 40...
November 2, 2016: Japanese Journal of Radiology
https://www.readbyqxmd.com/read/27797105/gradient-and-shim-pre-emphasis-by-inversion-of-a-linear-time-invariant-system-model
#15
S Johanna Vannesjo, Yolanda Duerst, Laetitia Vionnet, Benjamin E Dietrich, Matteo Pavan, Simon Gross, Christoph Barmet, Klaas P Pruessmann
PURPOSE: The goal of this contribution is to enhance the fidelity and switching speed of gradient and shim fields by advancing pre-emphasis toward broadband and full cross-term correction. THEORY AND METHODS: The proposed approach is based on viewing gradient and shim chains as linear, time-invariant (LTI) systems. Pre-emphasis is accomplished by inversion of a broadband digital system model. In the multiple-channel case, it amounts to a matrix of broadband filters that perform concerted self- and cross-term correction...
October 31, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/27791287/diffusion-tensor-spectroscopic-imaging-of-the-human-brain-in-children-and-adults
#16
Kevin Fotso, Stephen R Dager, Alec Landow, Elena Ackley, Orrin Myers, Mindy Dixon, Dennis Shaw, Neva M Corrigan, Stefan Posse
PURPOSE: We developed diffusion tensor spectroscopic imaging (DTSI), based on proton-echo-planar-spectroscopic imaging (PEPSI), and evaluated the feasibility of mapping brain metabolite diffusion in adults and children. METHODS: PRESS prelocalized DTSI at 3 Tesla (T) was performed using navigator-based correction of movement-related phase errors and cardiac gating with compensation for repetition time (TR) related variability in T1 saturation. Mean diffusivity (MD) and fractional anisotropy (FA) of total N-acetyl-aspartate (tNAA), total creatine (tCr), and total choline (tCho) were measured in eight adults (17-60 years) and 10 children (3-24 months) using bmax  = 1734 s/mm(2) , 1 cc and 4...
October 28, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/27779126/mr-compatibility-of-a-high-resolution-small-animal-pet-insert-operating-inside-a-7-t-mri
#17
J D Thiessen, E Shams, G Stortz, G Schellenberg, D Bishop, M S Khan, P Kozlowski, F Retière, V Sossi, C J Thompson, A L Goertzen
A full-ring PET insert consisting of 16 PET detector modules was designed and constructed to fit within the 114 mm diameter gradient bore of a Bruker 7 T MRI. The individual detector modules contain two silicon photomultiplier (SiPM) arrays, dual-layer offset LYSO crystal arrays, and high-definition multimedia interface (HDMI) cables for both signal and power transmission. Several different RF shielding configurations were assessed prior to construction of a fully assembled PET insert using a combination of carbon fibre and copper foil for RF shielding...
November 21, 2016: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/27776645/simultaneous-multi-slice-echo-planar-diffusion-weighted-imaging-of-the-liver-and-the-pancreas-optimization-of-signal-to-noise-ratio-and-acquisition-time-and-application-to-intravoxel-incoherent-motion-analysis
#18
Andreas Boss, Borna Barth, Lukas Filli, David Kenkel, Moritz C Wurnig, Marco Piccirelli, Caecilia S Reiner
PURPOSE: To optimize and test a diffusion-weighted imaging (DWI) echo-planar imaging (EPI) sequence with simultaneous multi-slice (SMS) excitation in the liver and pancreas regarding acquisition time (TA), number of slices, signal-to-noise ratio (SNR), image quality (IQ), apparent diffusion coefficient (ADC) quantitation accuracy, and feasibility of intravoxel incoherent motion (IVIM) analysis. MATERIALS AND METHODS: Ten healthy volunteers underwent DWI of the upper abdomen at 3T...
November 2016: European Journal of Radiology
https://www.readbyqxmd.com/read/27775896/detection-of-traumatic-bone-marrow-lesions-after-knee-trauma-comparison-of-adc-maps-derived-from-diffusion-weighted-imaging-with-standard-fat-saturated-proton-density-weighted-turbo-spin-echo-sequences
#19
Alexis Klengel, Patrick Stumpp, Steffen Klengel, Ina Böttger, Nadja Rönisch, Thomas Kahn
Purpose To compare single-shot echo-planar diffusion-weighted imaging-derived apparent diffusion coefficient (ADC) maps with fat-saturated (FS) proton density (PD)-weighted turbo spin-echo (TSE) imaging in the detection of bone marrow lesions (BMLs) after knee trauma. Materials and Methods Institutional review board approval was obtained from Leipzig University. Written informed consent was waived. Three radiologists retrospectively re-examined 97 consecutive patients with reported knee trauma who underwent 1...
October 24, 2016: Radiology
https://www.readbyqxmd.com/read/27774644/mri-with-phaseless-encoding
#20
Franciszek Hennel, Klaas P Pruessmann
PURPOSE: Fourier encoded MRI signal is complex and, therefore, sensitive to uncontrolled phase variations caused, e.g., by object motion. An alternative encoding is proposed which leads to phaseless (positive real) signals and allows the phase fluctuations to be removed by simple magnitude calculation before the Fourier transform. THEORY AND METHODS: Phaseless encoding uses harmonic modulation of the longitudinal magnetization with different frequencies and phases before excitation...
October 23, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
keyword
keyword
119314
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"