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https://www.readbyqxmd.com/read/29334131/a-bayesian-method-for-accelerated-magnetic-resonance-elastography-of-the-liver
#1
Christopher Ebersole, Rizwan Ahmad, Adam V Rich, Lee C Potter, Huiming Dong, Arunark Kolipaka
PURPOSE: Magnetic resonance elastography is a noninvasive tool for quantifying soft tissue stiffness. Magnetic resonance elastography has been adopted as a clinical method for staging liver fibrosis. However, the application of liver magnetic resonance elastography requires multiple lengthy breath-holds. We propose a new data acquisition and processing method to reduce magnetic resonance elastography scan time. METHODS: A Bayesian image reconstruction method that uses transform sparsity and magnitude consistency across different phase offsets to recover images from highly undersampled data is proposed...
January 15, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29327116/evaluation-of-hemodynamic-imaging-findings-of-hypervascular-hepatocellular-carcinoma-comparison-between-dynamic-contrast-enhanced-magnetic-resonance-imaging-using-radial-volumetric-imaging-breath-hold-examination-with-k-space-weighted-image-contrast-reconstruction
#2
Masahiro Kurozumi, Yasunari Fujinaga, Yoshihiro Kitou, Akira Yamada, Ayumi Ohya, Yasuo Adachi, Yoshinori Tsukahara, Marcel D Nickel, Katsuya Maruyama, Takeshi Uehara, Shin-Ichi Miyagawa, Masumi Kadoya
PURPOSE: To compare the visualization of hemodynamic imaging findings of hypervascular hepatocellular carcinoma (HCC) on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using radial volumetric imaging breath-hold examination with k-space-weighted image contrast reconstruction (r-VIBE-KWIC) versus dynamic computed tomography during hepatic arteriography (dyn-CTHA). MATERIALS AND METHODS: We retrospectively reviewed the databases of preoperative DCE-MRI using r-VIBE-KWIC, dyn-CTHA, and postoperative pathology of resected specimens...
January 11, 2018: Japanese Journal of Radiology
https://www.readbyqxmd.com/read/29299818/influence-of-the-reference-scan-and-scan-time-on-the-arterial-phase-of-liver-magnetic-resonance-imaging
#3
Yoshinori Tsuji, Satoshi Saitoh, Junji Takahashi, Chisato Abe, Tatsuya Hayashi, Masahiro Kobayashi
The controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) technique can decrease scan time. The purpose of this study was to determine whether an arterial phase scan can be performed in 5 s using the CAIPIRINHA short-scan and a reference scanning technique. The generalized autocalibrating partially parallel acquisition (GRAPPA), the CAIPIRINHA routine (CAIPI-routine), and the CAIPIRINHA short-scanning (CAIPI-short) methods were compared. The scan time for each method was preset to 20 s, 15 s, and 10 s, respectively...
January 3, 2018: Radiological Physics and Technology
https://www.readbyqxmd.com/read/29298692/an-in-vivo-comparison-of-stimulated-echo-and-motion-compensated-spin-echo-sequences-for-3%C3%A2-t-diffusion-tensor-cardiovascular-magnetic-resonance-at-multiple-cardiac-phases
#4
Andrew D Scott, Sonia Nielles-Vallespin, Pedro F Ferreira, Zohya Khalique, Peter D Gatehouse, Philip Kilner, Dudley J Pennell, David N Firmin
BACKGROUND: Stimulated-echo (STEAM) and, more recently, motion-compensated spin-echo (M2-SE) techniques have been used for in-vivo diffusion tensor cardiovascular magnetic resonance (DT-CMR) assessment of cardiac microstructure. The two techniques differ in the length scales of diffusion interrogated, their signal-to-noise ratio efficiency and sensitivity to both motion and strain. Previous comparisons of the techniques have used high performance gradients at 1.5 T in a single cardiac phase...
January 3, 2018: Journal of Cardiovascular Magnetic Resonance
https://www.readbyqxmd.com/read/29297607/signal-enhancement-ratio-imaging-of-the-lung-parenchyma-with-ultra-fast-steady-state-free-precession-mri-at-1-5t
#5
Orso Pusterla, Gregor Sommer, Francesco Santini, Mark Wiese, Didier Lardinois, Michael Tamm, Jens Bremerich, Grzegorz Bauman, Oliver Bieri
BACKGROUND: Lung perfusion MRI after i.v. gadolinium (Gd) contrast administration is commonly based on spoiled gradient-echo acquisitions, such as volume-interpolated breath-hold examinations (VIBE), suffering from low signal-to-noise in the parenchyma. PURPOSE: To investigate the lung signal enhancement ratio (SER) with ultra-fast steady-state free precession (ufSSFP) after Gd-administration. STUDY TYPE: Retrospective. SUBJECTS: Ten subjects with healthy lungs; nine patients with pulmonary diseases (chronic obstructive pulmonary disease [COPD], lung cancer, pulmonary fibrosis, lung contusion)...
January 3, 2018: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/29290405/ct-ventilation-imaging-derived-from-breath-hold-ct-exhibits-good-regional-accuracy-with-galligas-pet
#6
Enid M Eslick, John Kipritidis, Denis Gradinscak, Mark J Stevens, Dale L Bailey, Benjamin Harris, Jeremy T Booth, Paul J Keall
BACKGROUND AND PURPOSE: CT ventilation imaging (CTVI) derived from four dimensional CT (4DCT) has shown only moderate spatial accuracy in humans due to 4DCT image artefacts. Here we assess the accuracy of an improved CTVI using high quality exhale/inhale breath-hold CT (BHCT). MATERIALS AND METHODS: Eighteen lung cancer patients underwent exhale/inhale BHCT, 4DCT and Galligas PET ventilation scans in a single imaging session. For each BHCT and 4DCT scan, we performed deformable image registration (DIR) between the inhale and exhale phase images to quantify ventilation using three published metrics: (i) breathing induced lung density change, CTVIDIR-HU (ii) breathing induced volume change CTVIDIR-Jac and (iii) the regional air-tissue product, CTVIHU Spatial accuracy was reported as the voxel-wise Spearman correlation r between CTVI and Galligas PET...
December 28, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/29286486/whole-body-pet-mri-of-pediatric-patients-the-details-that-matter
#7
Anuj Pareek, Anne M Muehe, Ashok J Theruvath, Praveen K Gulaka, Sheri L Spunt, Heike E Daldrup-Link
Integrated PET/MRI is a hybrid imaging technique enabling clinicians to acquire diagnostic images for tumor assessment and treatment monitoring with both high soft tissue contrast and added metabolic information. Integrated PET/MRI has shown to be valuable in the clinical setting and has many promising future applications. The protocol presented here will provide step-by-step instructions for the acquisition of whole-body 2-deoxy-2-(18F)fluoro-D-glucose (18F-FDG) PET/MRI data in children with cancer. It also provides instructions on how to combine a whole-body staging scan with a local tumor scan for evaluation of the primary tumor...
December 19, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/29282752/self-gated-golden-angle-spiral-cine-mri-for-coronary-endothelial-function-assessment
#8
Gabriele Bonanno, Allison G Hays, Robert G Weiss, Michael Schär
PURPOSE: Depressed coronary endothelial function (CEF) is a marker for atherosclerotic disease, an independent predictor of cardiovascular events, and can be quantified non-invasively with ECG-triggered spiral cine MRI combined with isometric handgrip exercise (IHE). However, MRI-CEF measures can be hindered by faulty ECG-triggering, leading to prolonged breath-holds and degraded image quality. Here, a self-gated golden angle spiral method (SG-GA) is proposed to eliminate the need for ECG during cine MRI...
December 27, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29279157/pulmonary-nodule-detection-in-oncological-patients-value-of-respiratory-triggered-periodically-rotated-overlapping-parallel-t2-weighted-imaging-evaluated-with-pet-ct-mr
#9
Felipe de Galiza Barbosa, Jan Henning Geismar, Gaspar Delso, Michael Messerli, Martin Huellner, Paul Stolzmann, Patrick Veit-Haibach
PURPOSE: To prospectively evaluate the detection and conspicuity of pulmonary nodules in an oncological population, using a tri-modality PET/CT-MR protocol including a respiration-gated T2-PROPELLER sequence for possible integration into a simultaneous PET/MR protocol. METHODS: 149 patients referred for staging of malignancy were prospectively enrolled in this single-center study. Imaging was performed on a tri-modality PET/CT-MR setup and was comprised of PET/CT and 3T-MR imaging with 3D dual-echo GRE pulse sequence (Dixon) and an axial respiration-gated T2-weighted PROPELLER (T2-P) sequence...
January 2018: European Journal of Radiology
https://www.readbyqxmd.com/read/29279148/3d-hybrid-profile-order-technique-in-a-single-breath-hold-3d-t2-weighted-fast-spin-echo-sequence-usefulness-in-diagnosis-of-small-liver-lesions
#10
Kenichiro Hirata, Takeshi Nakaura, Tomoyuki Okuaki, Noriko Tsuda, Narumi Taguchi, Seitaro Oda, Daisuke Utsunomiya, Yasuyuki Yamashita
PURPOSE: We compared the efficacy of three-dimensional (3D) isotropic T2-weighted fast spin-echo imaging using a 3D hybrid profile order technique with a single-breath-hold (3D-Hybrid BH) with a two-dimensional (2D) T2-weighted fast spin-echo conventional respiratory-gated (2D-Conventional RG) technique for visualising small liver lesions. MATERIALS AND METHODS: This study was approved by our institutional review board. The requirement to obtain written informed consent was waived...
January 2018: European Journal of Radiology
https://www.readbyqxmd.com/read/29277267/placental-baseline-conditions-modulate-the-hyperoxic-bold-mri-response
#11
Marianne Sinding, David A Peters, Sofie S Poulsen, Jens B Frøkjær, Ole B Christiansen, Astrid Petersen, Niels Uldbjerg, Anne Sørensen
OBJECTIVES: Human pregnancies complicated by placental dysfunction may be characterized by a high hyperoxic Blood oxygen level-dependent (BOLD) MRI response. The pathophysiology behind this phenomenon remains to be established. The aim of this study was to evaluate whether it is associated with altered placental baseline conditions, including a lower oxygenation and altered tissue morphology, as estimated by the placental transverse relaxation time (T2*). METHOD: We included 49 normal pregnancies (controls) and 13 pregnancies complicated by placental dysfunction (cases), defined by a birth weight < 10th percentile in combination with placental pathological signs of vascular malperfusion...
January 2018: Placenta
https://www.readbyqxmd.com/read/29260366/feasibility-of-free-breathing-dynamic-contrast-enhanced-mri-of-gastric-cancer-using-a-golden-angle-radial-stack-of-stars-vibe-sequence-comparison-with-the-conventional-contrast-enhanced-breath-hold-3d-vibe-sequence
#12
Huan-Huan Li, Hui Zhu, Lei Yue, Yi Fu, Robert Grimm, Alto Stemmer, Cai-Xia Fu, Wei-Jun Peng
OBJECTIVES: To investigate the feasibility and diagnostic value of free-breathing, radial, stack-of-stars three-dimensional (3D) gradient echo (GRE) sequence ("golden angle") on dynamic contrast-enhanced (DCE) MRI of gastric cancer. METHODS: Forty-three gastric cancer patients were divided into cooperative and uncooperative groups. Respiratory fluctuation was observed using an abdominal respiratory gating sensor. Those who breath-held for more than 15 s were placed in the cooperative group and the remainder in the uncooperative group...
December 19, 2017: European Radiology
https://www.readbyqxmd.com/read/29237965/investigating-different-computed-tomography-techniques-for-internal-target-volume-definition
#13
S A Yoganathan, K J Maria Das, V Siva Subramanian, D Gowtham Raj, Arpita Agarwal, Shaleen Kumar
PURPOSE: The aim of this work was to evaluate the various computed tomography (CT) techniques such as fast CT, slow CT, breath-hold (BH) CT, full-fan cone beam CT (FF-CBCT), half-fan CBCT (HF-CBCT), and average CT for delineation of internal target volume (ITV). In addition, these ITVs were compared against four-dimensional CT (4DCT) ITVs. MATERIALS AND METHODS: Three-dimensional target motion was simulated using dynamic thorax phantom with target insert of diameter 3 cm for ten respiration data...
October 2017: Journal of Cancer Research and Therapeutics
https://www.readbyqxmd.com/read/29222852/free-breathing-whole-heart-3d-cine-magnetic-resonance-imaging-with-prospective-respiratory-motion-compensation
#14
Mehdi H Moghari, Ashita Barthur, Maria E Amaral, Tal Geva, Andrew J Powell
PURPOSE: To develop and validate a new prospective respiratory motion compensation algorithm for free-breathing whole-heart 3D cine steady-state free precession (SSFP) imaging. METHODS: In a 3D cine SSFP sequence, 4 excitations per cardiac cycle are re-purposed to prospectively track heart position. Specifically, their 1D image is reconstructed and routed into the scanner's standard diaphragmatic navigator processing system. If all 4 signals are in end-expiration, cine image data from the entire cardiac cycle is accepted for image reconstruction...
December 8, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29210110/paediatric-breath-holding-spells-are-associated-with-autonomic-dysfunction-and-iron-deficiency-may-play-a-role
#15
H Tomoum, N Habeeb, I Elagouza, H Mobarez
AIM: This study assessed cardiac performance and iron in subjects aged 12-36 months with breath-holding spells (BHS). METHODS: We consecutively recruited 40 subjects (55% male) experiencing BHS from the general paediatric outpatients department at the Children's Hospital, Ain Shams University, Egypt from 2015-2016. The 20 matched comparisons were mainly healthy siblings. The workup included iron levels and electrocardiograms. RESULTS: The age at the onset of BHS was 5-24 months with a median monthly frequency of 13...
December 6, 2017: Acta Paediatrica
https://www.readbyqxmd.com/read/29205623/improvement-of-the-repeatability-of-parallel-transmission-at-7t-using-interleaved-acquisition-in-the-calibration-scan
#16
Hiroyuki Kameda, Kohsuke Kudo, Tsuyoshi Matsuda, Taisuke Harada, Yuji Iwadate, Ikuko Uwano, Fumio Yamashita, Kunihiro Yoshioka, Makoto Sasaki, Hiroki Shirato
BACKGROUND: Respiration-induced phase shift affects B0 /B1+ mapping repeatability in parallel transmission (pTx) calibration for 7T brain MRI, but is improved by breath-holding (BH). However, BH cannot be applied during long scans. PURPOSE: To examine whether interleaved acquisition during calibration scanning could improve pTx repeatability and image homogeneity. STUDY TYPE: Prospective. SUBJECTS: Nine healthy subjects...
December 4, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/29204519/cardiac-sparing-radiation-therapy-using-positioning-breast-shell-for-patients-with-left-sided-breast-cancer-who-are-ineligible-for-breath-hold-techniques
#17
Kurian Joseph, Heather Warkentin, Sunita Ghosh, Lee-Anne Polkosnik, Kent Powell, Matthew Brennan, Brad Warkentin, Johanna Jacobs, Khalifa Alkaabi, Susan Chafe, Keith Tankel, Zsolt Gabos, Hong-Wei Liu, Patricia Tai
Purpose: Patients with left-sided breast cancer (LSBC) are at increased risk of cardiac morbidity from adjuvant breast radiation therapy (ABRT). Breath-hold (BH) techniques substantially reduce the radiation received by heart during radiation therapy for LSBC. However, a subset of patients with LSBC are ineligible for BH techniques due to an inability to breath-hold or because of other comorbidities. To reduce radiation to the heart, we routinely use a custom-made breast shell for the treatment of patients with LSBC who are ineligible for BH techniques...
October 2017: Advances in Radiation Oncology
https://www.readbyqxmd.com/read/29202394/common-errors-made-in-attempt-to-contract-the-pelvic-floor-muscles-in-women-early-after-delivery-a-prospective-observational-study
#18
Hedwig Neels, Stefan De Wachter, Jean-Jacques Wyndaele, Tinne Van Aggelpoel, Alexandra Vermandel
OBJECTIVES: The ability to perform a correct pelvic floor muscle contraction (PFMC) is necessary to start pelvic floor muscle training after delivery. COMMOV are "c"ontractions of "o"ther "m"uscles (m. rectus abdominus, the gluteal muscles, and the adductors), and other "mov"ements (pelvic tilt, breath holding, and straining) performed in addition to or instead of the PFMC. COMMOV are probably the most common errors in attempt to contract the pelvic floor muscles during the first days after delivery...
January 2018: European Journal of Obstetrics, Gynecology, and Reproductive Biology
https://www.readbyqxmd.com/read/29195556/immobilization-for-carbon-ion-beam-ablation-of-cardiac-structures-in-a-porcine-model
#19
Matthias Prall, Anna Eichhorn, Daniel Richter, H Immo Lehmann, Anna Constantinescu, Robert Kaderka, Patrick Lugenbiel, Dierk Thomas, Christoph Bert, Douglas L Packer, Marco Durante, Christian Graeff
INTRODUCTION: Whereas hadron therapy of static targets is clinically established, treatment of moving organs remains a challenge. One strategy is to minimize motion of surrounding tissue mechanically and to mitigate residual motion with an appropriate irradiation technique. In this technical note, we present and characterize such an immobilization technique for a novel noncancerous application: the irradiation of small targets in hearts with scanned carbon ion beams in a porcine model for elimination of arrhythmias...
November 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/29194732/doppler-ultrasound-triggering-for-cardiac-mri-at-7t
#20
F Kording, C Ruprecht, B Schoennagel, K Fehrs, J Yamamura, G Adam, J Goebel, K Nassenstein, S Maderwald, H H Quick, O Kraff
PURPOSE: A prerequisite for cardiac MR (CMR) imaging is adequate synchronization of image acquisition with the cardiac cycle. Electrocardiogram triggering may be hampered by electromagnetic interferences at high field strength. The purpose of this work is to evaluate the feasibility of Doppler ultrasound triggering for CMR image synchronization at 7T ultra-high-field MRI. METHODS: A custom-built Doppler ultrasound (DUS) trigger device was developed. Magnetic resonance compatibility was evaluated using E- and H-field probes and flip angle maps prior to the study...
December 1, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
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