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https://www.readbyqxmd.com/read/28081157/simultaneous-quantitative-mri-mapping-of-t1-t2-and-magnetic-susceptibility-with-multi-echo-mp2rage
#1
Riccardo Metere, Tobias Kober, Harald E Möller, Andreas Schäfer
The knowledge of relaxation times is essential for understanding the biophysical mechanisms underlying contrast in magnetic resonance imaging. Quantitative experiments, while offering major advantages in terms of reproducibility, may benefit from simultaneous acquisitions. In this work, we demonstrate the possibility of simultaneously recording relaxation-time and susceptibility maps with a prototype Multi-Echo (ME) Magnetization-Prepared 2 RApid Gradient Echoes (MP2RAGE) sequence. T1 maps can be obtained using the MP2RAGE sequence, which is relatively insensitive to inhomogeneities of the radio-frequency transmit field, [Formula: see text]...
2017: PloS One
https://www.readbyqxmd.com/read/28078511/intra-individual-comparison-of-different-gadolinium-based-contrast-agents-in-the-quantitative-evaluation-of-c6-glioma-with-dynamic-contrast-enhanced-magnetic-resonance-imaging
#2
Ying Li, Gang Liu, Xin Lou, Zhiye Chen, Lin Ma
This experiment aimed to compare the ionic (Gadodiamide, Gd-DTPA-BMA) and non-ionic (Gadopentetate dimeglumine, Gd-DTPA) gadolinium-based contrast agents (GBCA) in the quantitative evaluation of C6 glioma with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). A C6 glioma model was established in 12 Wistar rats, and magnetic resonance (MR) scans were performed six days after tumor implantation. Imaging was performed using a 3.0-T MR scanner with a 7-inch handmade circular coil. Pre-contrast T1 mapping and dynamic contrast-enhanced T1WI after a bolus injection (0...
January 4, 2017: Science China. Life Sciences
https://www.readbyqxmd.com/read/28077267/rapid-whole-brain-myelin-water-content-mapping-without-an-external-water-standard-at-1-5t
#3
Thanh D Nguyen, Pascal Spincemaille, Susan A Gauthier, Yi Wang
The objective of this study is to develop rapid whole brain mapping of myelin water content (MWC) at 1.5T. The Fast Acquisition with Spiral Trajectory and T2prep (FAST-T2) pulse sequence originally developed for myelin water fraction (MWF) mapping was modified to obtain fast mapping of T1 and receiver coil sensitivity needed for MWC computation. The accuracy of the proposed T1 mapping was evaluated by comparing with the standard IR-FSE method. Numerical simulations were performed to assess the accuracy and reliability of the proposed MWC mapping...
January 7, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28070844/gd-eob-dtpa-enhanced-mri-t1-mapping-for-assessment-of-liver-function-in-rabbit-fibrosis-model-comparison-of-hepatobiliary-phase-images-obtained-at-10-and-20%C3%A2-min
#4
Zhi-Peng Zhou, Li-Ling Long, Li-Juan Huang, Teng-Fei Yang, Zhong-Kui Huang
OBJECTIVES: To compare hepatobiliary phase (HBP) images obtained at 10 and 20 min after Gd-EOB-DTPA-enhanced MRI for assessment of liver function in rabbit fibrosis model on 3.0 T MR imaging. METHODS: 34 animals were separated into three groups: 5 for a control group, 14 for a mild fibrosis group, and 15 for a severe fibrosis group based on pathological proof. T1 relaxation times (T1rt) were measured on T1 mapping and reduction rates of T1rt (rrT1rt) were calculated...
January 9, 2017: La Radiologia Medica
https://www.readbyqxmd.com/read/28065371/real-t1-relaxation-time-measurement-and-diurnal-variation-analysis-of-intervertebral-discs-in-a-healthy-population-of-50-volunteers
#5
J Galley, G Maestretti, G Koch, H-M Hoogewoud
PURPOSE: To measure the real T1 relaxation time of the lumbar intervertebral discs in a young and healthy population, using different inversion recovery times, and assess diurnal variation. MATERIAL AND METHODS: Intervertebral discs from D12 to S1 of 50 healthy volunteers from 18 to 25 years old were evaluated twice the same day, in the morning and in the late afternoon. Dedicated MRI sequences with different inversion recovery times (from 100 to 2500ms) were used to calculate the real T1 relaxation time...
February 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28050692/effect-of-inversion-time-on-the-precision-of-myocardial-late-gadolinium-enhancement-quantification-evaluated-with-synthetic-inversion-recovery-mr-imaging
#6
Akos Varga-Szemes, Rob J van der Geest, U Joseph Schoepf, Bruce S Spottiswoode, Carlo N De Cecco, Giuseppe Muscogiuri, Julian L Wichmann, Stefanie Mangold, Stephen R Fuller, Pal Maurovich-Horvat, Bela Merkely, Sheldon E Litwin, Rozemarijn Vliegenthart, Pal Suranyi
OBJECTIVES: To evaluate the influence of inversion time (TI) on the precision of myocardial late gadolinium enhancement (LGE) quantification using synthetic inversion recovery (IR) imaging in patients with myocardial infarction (MI). METHODS: Fifty-three patients with suspected prior MI underwent 1.5-T cardiac MRI with conventional magnitude (MagIR) and phase-sensitive IR (PSIR) LGE imaging and T1 mapping at 15 min post-contrast. T1-based synthetic MagIR and PSIR images were calculated with a TI ranging from -100 to +150 ms at 5-ms intervals relative to the optimal TI (TI0)...
January 3, 2017: European Radiology
https://www.readbyqxmd.com/read/28047962/tu-h-206-03-characterizing-b1-inhomogeneities-in-dce-mri
#7
H Gach, N Mason
PURPOSE: Dynamic Contrast Enhanced (DCE) MRI is a valuable technique for measuring perfusion and permeability characteristics of tumors. Exogenous contrast concentrations are calculated based on changes in T1 measured using fast 3D gradient echo (FLASH) sequences. However, the slab selective pulses used in 3D MRI may result in B1 inhomogeneities across the volume of interest that can lead to errors in T1 and thus the estimated gadolinium concentration. We compared three FLASH DCE sequences (GRE, TWIST, and VIBE) to determine their signal homogeneity across slices and the accuracy in calculating T1 using acquisitions with variable flip angles...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047863/tu-h-206-06-b1-inhomogeneity-correction-for-measuring-t1-from-dce-mri
#8
H Gach, N Mason, H Wang, C Tsien, T Benzinger, C Robinson
PURPOSE: 3D MRI sequences typically used in DCE MRI suffer from B1 inhomogeneities associated with the slab-selective RF pulse. B1 inhomogeneities affect the calculation of tissue T1 often used to solve the two-compartment model. Previously, the inhomogeneities were corrected based on Bloch equation simulations of the RF pulse. However, the RF pulse specification may not be readily available or the simulation may not represent the actual scan conditions. The objective of this work was to directly measure B1 inhomogeneities and apply an inhomogeneity correction to minimize quantification errors in T1 fitting...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047779/we-h-207a-08-characterization-of-a-broad-spectrum-cancer-targeted-mri-contrast-agent
#9
C Brunnquell, R Zhang, A Pinchuk, J Weichert
PURPOSE: To characterize the relaxation properties and tumor targeting capabilities of a novel alkylphosphocholine (APC) analog MR contrast agent, Gd-DO3A-404. METHODS: Relaxivities were measured via T1 and T2 mapping of Gd-DO3A-404 with inversion recovery and spin echo pulse sequences, respectively. Uptake was characterized in flank xenograft models of non-small cell lung cancer (A549) and glioma (U87) and compared with uptake of Dotarem. Mice (N=3 per model per agent) were delivered 2...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28031392/dce-mri-blood-brain-barrier-assessment-in-acute-ischemic-stroke
#10
Kersten Villringer, Borja E Sanz Cuesta, Ann-Christin Ostwaldt, Ulrike Grittner, Peter Brunecker, Ahmed A Khalil, Kristina Schindler, Ole Eisenblätter, Heinrich Audebert, Jochen B Fiebach
OBJECTIVE: To quantitatively evaluate blood-brain barrier changes in ischemic stroke patients using dynamic contrast-enhanced (DCE) MRI. METHODS: We examined 54 stroke patients (clinicaltrials.gov NCT00715533, NCT02077582) in a 3T MRI scanner within 48 hours after symptom onset. Twenty-eight patients had a follow-up examination on day 5-7. DCE T1 mapping and Patlak analysis were employed to assess BBB permeability changes. RESULTS: Median stroke K(trans) values (0...
December 28, 2016: Neurology
https://www.readbyqxmd.com/read/28027767/t1-mapping-cardiovascular-magnetic-resonance-imaging-to-detect-myocarditis-impact-of-slice-orientation-on-the-diagnostic-performance
#11
Sebastian Bohnen, Ulf K Radunski, Gunnar K Lund, Enver Tahir, Maxim Avanesov, Christian Stehning, Bernhard Schnackenburg, Gerhard Adam, Stefan Blankenberg, Kai Muellerleile
BACKGROUND: T1 mapping is a promising diagnostic tool to improve the diagnostic accuracy of cardiovascular magnetic resonance (CMR) in patients with suspected myocarditis. However, there are currently no data on the potential influence of slice orientation on the diagnostic performance of CMR. Thus, we compared the diagnostic performance of global myocardial T1 and extracellular volume (ECV) values to differentiate patients with myocarditis from healthy individuals between different slice orientations...
January 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28017384/myocardial-fibrosis-and-cardiac-decompensation-in-aortic-stenosis
#12
Calvin W L Chin, Russell J Everett, Jacek Kwiecinski, Alex T Vesey, Emily Yeung, Gavin Esson, William Jenkins, Maria Koo, Saeed Mirsadraee, Audrey C White, Alan G Japp, Sanjay K Prasad, Scott Semple, David E Newby, Marc R Dweck
OBJECTIVES: Cardiac magnetic resonance (CMR) was used to investigate the extracellular compartment and myocardial fibrosis in patients with aortic stenosis, as well as their association with other measures of left ventricular decompensation and mortality. BACKGROUND: Progressive myocardial fibrosis drives the transition from hypertrophy to heart failure in aortic stenosis. Diffuse fibrosis is associated with extracellular volume expansion that is detectable by T1 mapping, whereas late gadolinium enhancement (LGE) detects replacement fibrosis...
December 8, 2016: JACC. Cardiovascular Imaging
https://www.readbyqxmd.com/read/28003137/a-feasible-and-automatic-free-tool-for-t1-and-ecv-mapping
#13
Luisa Altabella, Cristian Borrazzo, Marco Carnì, Nicola Galea, Marco Francone, Andrea Fiorelli, Elisabetta Di Castro, Carlo Catalano, Iacopo Carbone
PURPOSE: Cardiac magnetic resonance (CMR) is a useful non-invasive tool for characterizing tissues and detecting myocardial fibrosis and edema. Estimation of extracellular volume fraction (ECV) using T1 sequences is emerging as an accurate biomarker in cardiac diseases associated with diffuse fibrosis. In this study, automatic software for T1 and ECV map generation consisting of an executable file was developed and validated using phantom and human data. METHODS: T1 mapping was performed in phantoms and 30 subjects (22 patients and 8 healthy subjects) on a 1...
December 18, 2016: Physica Medica: PM
https://www.readbyqxmd.com/read/27997439/structural-and-functional-correlates-of-myocardial-t1-mapping-in-321-patients-with-hypertrophic-cardiomyopathy
#14
Linda C Chu, Celia P Corona-Villalobos, Marc K Halushka, Yan Zhang, Chiara Pozzessere, Ihab R Kamel, Iraklis Pozios, Rob J Van Der Geest, Neville Gai, Roselle M Abraham, Theodore P Abraham, David A Bluemke, Stefan L Zimmerman
OBJECTIVE: The aim of this study was to evaluate the structural and functional correlates of T1 mapping in 321 patients with hypertrophic cardiomyopathy (HCM). METHODS: Three hundred twenty-one patients with HCM who underwent cardiac magnetic resonance from 2003 to 2013 were retrospectively identified from our institution's HCM registry. Left ventricular volume, function, late gadolinium enhancement (LGE), and Look-Locker T1 time were quantified. T1 time was normalized to blood pool to calculate T1 ratio...
December 15, 2016: Journal of Computer Assisted Tomography
https://www.readbyqxmd.com/read/27995976/in-vivo-memri-characterization-of-brain-metastases-using-a-3d-look-locker-t1-mapping-sequence
#15
Charles R Castets, Néha Koonjoo, Andreea Hertanu, Pierre Voisin, Jean-Michel Franconi, Sylvain Miraux, Emeline J Ribot
Although MEMRI (Manganese Enhanced MRI) informations were obtained on primary tumors in small animals, MEMRI data on metastases are lacking. Thus, our goal was to determine if 3D Look-Locker T1 mapping was an efficient method to evaluate Mn ions transport in brain metastases in vivo. The high spatial resolution in 3D (156 × 156 × 218 μm) of the sequence enabled to detect metastases of 0.3 mm(3). In parallel, the T1 quantitation enabled to distinguish three populations of MDA-MB-231 derived brain metastases after MnCl2 intravenous injection: one with a healthy blood-tumor barrier that did not internalize Mn(2+) ions, and two others, which T1 shortened drastically by 54...
December 20, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27989908/fast-t1-mapping-of-the-brain-at-high-field-using-look-locker-and-fast-imaging
#16
Ke Jiang, Yanjie Zhu, Sen Jia, Yin Wu, Xin Liu, Yiu-Cho Chung
This study aims to develop and evaluate a new method for fast high resolution T1 mapping of the brain based on the Look-Locker technique. Single-shot turboflash sequence with high temporal acceleration is used to sample the recovery of inverted magnetization. Multi-slice interleaved acquisition within one inversion slab is used to reduce the number of inversion pulses and hence SAR. Accuracy of the proposed method was studied using simulation and validated in phantoms. It was then evaluated in healthy volunteers and stroke patients...
October 27, 2016: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/27986796/association-of-cardiovascular-risk-factors-and-myocardial-fibrosis-with-early-cardiac-dysfunction-in-type-1-diabetes-the-diabetes-control-and-complications-trial-epidemiology-of-diabetes-interventions-and-complications-study
#17
Anderson C Armstrong, Bharath Ambale-Venkatesh, Evrim Turkbey, Sirisha Donekal, Elzbieta Chamera, Jye-Yu Backlund, Patricia Cleary, John Lachin, David A Bluemke, João A C Lima
OBJECTIVE: We investigated the association of cardiovascular risk factors and myocardial fibrosis with early cardiac dysfunction in type 1 diabetes. RESEARCH DESIGN AND METHODS: Participants with type 1 diabetes aged 13-39 years without a known history of cardiovascular disease (CVD) (n = 1,441) were recruited into the Diabetes Control and Complications Trial (1983-1993) and subsequently followed in the Epidemiology of Diabetes Interventions and Complications study (1994 to present)...
December 16, 2016: Diabetes Care
https://www.readbyqxmd.com/read/27986173/liver-function-assessment-by-magnetic-resonance-imaging
#18
Emre Ünal, Deniz Akata, Musturay Karcaaltincaba
Liver function assessment by hepatocyte-specific contrast-enhanced magnetic resonance imaging is becoming a new biomarker. Liver function can be assessed by T1 mapping (reduction rate) and signal intensity measurement (relative enhancement ratio) before and after GD-EOB-DTPA (gadoxetic acid) administration, as alternative to Tc-99m galactosyl serum albumin scintigraphy, 99m Tc-labeled mebrofenin scintigraphy, and indocyanine green clearance test. Magnetic resonance imaging assessment of liver function can enable diagnosis of cirrhosis, nonalcoholic fatty liver disease associated fibrosis and steatohepatitis, primary sclerosing cholangitis, toxic hepatitis, and chemotherapy and radiotherapy-related changes, which may be only visible on hepatobiliary phase images...
December 2016: Seminars in Ultrasound, CT, and MR
https://www.readbyqxmd.com/read/27974408/interstitial-fibrosis-functional-status-and-outcomes-in-heart-failure-with-preserved-ejection-fraction-insights-from-a-prospective-cardiac-magnetic-resonance-imaging-study
#19
Franz Duca, Andreas A Kammerlander, Caroline Zotter-Tufaro, Stefan Aschauer, Marianne L Schwaiger, Beatrice A Marzluf, Diana Bonderman, Julia Mascherbauer
BACKGROUND: Myocardial extracellular volume (ECV) accumulation is one of the key pathophysiologic features of heart failure with preserved ejection fraction (HFpEF). Our aims were to (1) measure ECV by cardiac magnetic resonance T1 mapping using the modified Look-Locker inversion recovery (MOLLI) sequence, (2) validate MOLLI-ECV against histology, and (3) investigate the relationship between MOLLI-ECV and prognosis in HFpEF. METHODS AND RESULTS: One-hundred seventeen consecutive HFpEF patients underwent cardiac magnetic resonance imaging, coronary angiography, and invasive hemodynamic assessments at baseline...
December 2016: Circulation. Cardiovascular Imaging
https://www.readbyqxmd.com/read/27955698/histologic-validation-of-myocardial-fibrosis-measured-by-t1-mapping-a-systematic-review-and-meta-analysis
#20
Kai-Yue Diao, Zhi-Gang Yang, Hua-Yan Xu, Xi Liu, Qin Zhang, Ke Shi, Li Jiang, Lin-Jun Xie, Ling-Yi Wen, Ying-Kun Guo
BACKGROUND: Myocardial fibrosis is being increasingly recognised as a common final pathway of a wide range of diseases. Thus, the development of an accurate and convenient method to evaluate myocardial fibrosis is of major importance. Although T1 mapping is a potential alternative for myocardial biopsy, validation studies are limited to small numbers and vary regarding technical facets, and include only a restricted number of disease. A systematic review and meta-analysis was conducted to objectively and comprehensively evaluate the performance of T1 mapping on the quantification of myocardial fibrosis using cardiovascular magnetic resonance (CMR)...
December 12, 2016: Journal of Cardiovascular Magnetic Resonance
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