Abstract:
PURPOSE:Single-scan two-dimensional MRI has been generally constrained to acquisitions in high quality magnets. This study introduces a methodology, cross-term spatiotemporal encoding (xSPEN), that delivers such images under much poorer external field conditions. METHODS:xSPEN departs from conventional k-space scanning, by relying on spatiotemporally encoding the image being sought. Unlike hitherto proposed SPEN methods, however, xSPEN's image readout does not take place using a field gradient along the direction being probed, but rather with the aid of an ancillary source of inhomogeneous frequency broadening. This ancillary dimension was here imposed by an orthogonal field gradient; for example, images along the "y" axis were read out by application of a "z" gradient. The principles and characteristics of this new approach, compatible with existing scanners and free from the need to collect auxiliary information such as field maps, are presented and discussed. RESULTS:Single- and multi-slice in vitro, ex vivo, and in vivo MRI experiments, confirmed the unusual resilience of this new single-shot MRI method to multiple chemical sites on phantoms, animals and humans. CONCLUSION:xSPEN can deliver single-scan MRI with good sensitivity and exceptional resilience to field inhomogeneities. This could enable investigations that have hitherto escaped from MRI's scope. Magn Reson Med 77:623-634, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Zhang Z,Seginer A,Frydman Ldoi
10.1002/mrm.26145subject
Has Abstractpub_date
2017-02-01 00:00:00pages
623-634issue
2eissn
0740-3194issn
1522-2594journal_volume
77pub_type
杂志文章abstract::High-resolution magic-angle spinning has become a valuable tool to study biologic samples; however, there are only a few high-resolution magic-angle spinning methodologies that have been explored specifically to deal with small semisolid biomaterials such as tissues. Here, we report a novel high-resolution (1)H NMR sp...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22231
更新日期:2010-02-01 00:00:00
abstract::In vivo 1H MRS can be used to detect and quantify the lactate resonance at 1.3 ppm provided that overlapping lipid resonances are eliminated. A homonuclear spectral editing method was developed to acquire uncontaminated 1H spectra of lactate with adiabatic pulses. An advantage of the adiabatic pulse sequence is the ab...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910300105
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abstract:PURPOSE:To separate the spectrally overlapped lactate and lipid signals at 1.3 ppm using diffusion-weighted magnetic resonance spectroscopy (DW-MRS) based on their large diffusivity difference. METHODS:DW-MRS was applied to the gel phantoms containing lactate and lipid droplets, and to the rat brain tumors. Lactate an...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26144
更新日期:2017-02-01 00:00:00
abstract::Spatial resolution in 3D breath-hold coronary MR angiography (MRA) is limited by imaging time. The purpose of this work was to investigate the feasibility of improving the spatial resolution of coronary MRA using generalized autocalibrating partially parallel acquisition (GRAPPA) and fast imaging with steady state pre...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20153
更新日期:2004-07-01 00:00:00
abstract::A double-echo two-excitation pulse sequence encoding fat and water signals for a phase-sensitive three-point Dixon-type analysis (DE-3PD) was developed and implemented on a 1.5 T MR imager. Data processing was performed using a previously developed two-dimensional (2D) region-growing algorithm, adapted to use double-e...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910340118
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abstract::The aim of this study was to detect salvageable peri-infarction myocardium by MRI in rats after infarction, using with a double contrast agent (CA) protocol at 7 Tesla. Intravascular superparamagnetic iron oxide (SPIO) nanoparticles and an extracellular paramagnetic CA (Gd-DOTA) were used to characterize the peri-infa...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20210
更新日期:2004-10-01 00:00:00
abstract::This study investigates the potential of in vivo 31P magnetic resonance spectroscopy (MRS) to characterize musculoskeletal tumors and to determine preoperative levels of histological necrosis, which is an important clinical indicator of patient response. Pretherapy MRS was performed on 28 patients with large musculosk...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910270204
更新日期:1992-10-01 00:00:00
abstract:PURPOSE:To develop and evaluate a method for RF envelope correction without extra hardware or synchronization. METHODS:Transmitted RF waveforms are measured through a simple pulse sequence called the gradient reversal approach to evaluate RF (GRATER). The measured RF waveforms are used to compute predistorted RF wavef...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.27930
更新日期:2020-01-01 00:00:00
abstract::A method for calculating quantitative three-dimensional susceptibility maps from field measurements acquired using gradient echo imaging at high field is presented. This method is based on division of the three-dimensional Fourier transforms of high-pass-filtered field maps by a simple function that is the Fourier tra...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.22334
更新日期:2010-05-01 00:00:00
abstract::T2-weighted MRI of edema in acute myocardial infarction (MI) provides a means of differentiating acute and chronic MI, and assessing the area at risk of infarction. Conventional T2-weighted imaging of edema uses a turbo spin-echo (TSE) readout with dark-blood preparation. Clinical applications of dark-blood TSE method...
journal_title:Magnetic resonance in medicine
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更新日期:2007-05-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25848
更新日期:2016-07-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910060212
更新日期:1988-02-01 00:00:00
abstract::Uncertainty regarding the intracellular/extracellular distribution of inorganic phosphate (P(i)) in tumors has raised concerns that pH calculated from the tumor P(i) chemical shift may not accurately represent the intracellular pH (pHin). This issue was addressed in subcutaneously transplanted murine radiation induced...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910360508
更新日期:1996-11-01 00:00:00
abstract:PURPOSE:To develop an analytically based algorithm for rapid optimization of the local radiofrequency magnetic (B1+) field intensity for a given radiofrequency power through a transmit array. The analytical nature of the method will yield insight to optimization requirements and provides a valuable reference for numeri...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24653
更新日期:2014-01-01 00:00:00
abstract::Functional MRI studies to date have been generally performed using the blood oxygenation level dependent (BOLD) contrast mechanism. Recently, it has been proposed that dynamic change in the apparent diffusion coefficient (ADC), measured using intravoxel incoherent motion (IVIM) weighting, can be used as a robust funct...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20293
更新日期:2004-12-01 00:00:00
abstract::We applied MRI to the in vivo detection of spontaneous colorectal tumors in a unique mouse model, the Fox Chase Cancer Center (FCCC) ApcMIN mouse. Unlike other Min (multiple intestinal neoplasia) strains, FCCC ApcMIN animals develop an appreciable number of tumors in the large intestine, which makes them an appropriat...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20175
更新日期:2004-09-01 00:00:00
abstract::Parallel excitation is being studied intensively for applications in MR imaging and in particular for selecting arbitrary shapes as regions of interest. In this work, parallel excitation was applied to arbitrarily shaped voxel selection in spectroscopy and investigated for different excitation k-space trajectories (ra...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.23018
更新日期:2012-02-01 00:00:00
abstract:PURPOSE:Quantitative mapping of the native T1 of the heart using the modified look-locker inversion recovery (MOLLI) technique provides high quality diagnostic information without requiring contrast agents. Previous work has considered the effects of T2 relaxation on MOLLI T1 measurements, finding that the T1 measured ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24867
更新日期:2013-09-01 00:00:00
abstract::Gradient-recalled echo-planar (T2*-weighted) imaging was used to noninvasively monitor regional blood oxygenation state changes in real time during transient episodes of focal ischemia in cat brain. Varying ischemic intervals (12 s to 30 min) were caused by middle cerebral artery occlusion. A rapid signal drop was not...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910270220
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abstract::Among previous analyses of the steady-state free-precession (SSFP) signal in rapid MRI, one treatment resulted in equations that require the evaluation of infinite binomial series. Here, an analytical solution is derived by a transformation into the power series expansion of the derivative of the inverse sine function...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.10410
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abstract::A three-axis uniplanar gradient coil was designed and built to provide order-of-magnitude increases in gradient strength of up to 500 mT/m on the x- and y-axes, and 1000 mT/m for the z-axis at 640 A input over a limited FOV ( approximately 16 cm) for superficial regions, compared to conventional gradient coils, with s...
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doi:10.1002/mrm.21263
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journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.1910040214
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journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.1910330306
更新日期:1995-03-01 00:00:00
abstract:PURPOSE:Establishing a high-resolution non-ECG-gated first-pass perfusion (FPP) cardiac MRI technique may improve accessibility and diagnostic capability of FPP imaging. We propose a non-ECG-gated FPP imaging technique using continuous magnetization-driven golden-angle radial acquisition. The main purpose of this preli...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25074
更新日期:2014-12-01 00:00:00
abstract::In order to obtain proton magnetic resonance spectra from the normal human kidney in vivo, we employed a STEAM sequence with delay times TE = 10 ms and TM = 30 ms. Signals are attenuated during STEAM sequences by J-coupling effects and by macroscopic movement of the sample. The combination of short echo times and resp...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910310503
更新日期:1994-05-01 00:00:00
abstract:PURPOSE:To improve multichannel compressed sensing (CS) reconstruction for MR proton resonance frequency (PRF) shift thermography, with application to MRI-induced RF heating evaluation and MR guided high intensity focused ultrasound (MRgFUS) temperature monitoring. METHODS:A new compressed sensing reconstruction is pr...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.27666
更新日期:2019-06-01 00:00:00
abstract::Magnetic resonance (MR) imaging and relaxation time measurements of bioresorbable implants made of polylactic acid (PLA), as well as the surrounding tissues, were carried out over a period of 6 months to monitor the implant state and the body's responses, and to determine how these processes are reflected in MR data. ...
journal_title:Magnetic resonance in medicine
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doi:10.1002/(sici)1522-2594(199907)42:1<210::aid-mrm29
更新日期:1999-07-01 00:00:00
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journal_title:Magnetic resonance in medicine
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更新日期:2016-10-01 00:00:00
abstract::Quantitative 1H MRS to determine cerebral metabolite patterns and MRI to determine CSF flow were applied to 12 patients with ventricular dilation-Group A, cortical atrophy (N = 5); or Group B, hydrocephalus (N = 7)- and in 9 normal controls. While mean brain water (Group A = 80% +/- 6; Group B = 86% +/- 5; normal = 85...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.1910370317
更新日期:1997-03-01 00:00:00