Abstract:
:A modified Look-Locker acquisition using saturation recovery (MLLSR) for breath-held myocardial T(1) mapping is presented. Despite its reduced dynamic range, saturation recovery enables substantially higher imaging efficiency than conventional inversion recovery T(1) mapping because it does not require time for magnetization to relax to equilibrium. Therefore, MLLSR enables segmented readouts, shorter data acquisition windows, and shorter breath holds compared with inversion recovery. T(1) measurements in phantoms using MLLSR showed a high correlation with conventional single-point inversion recovery spin echo. In vivo T(1) measurements from normal and infarcted myocardium in 41 volunteers and patients were consistent with previously reported values. Twenty subjects were also scanned with MLLSR using an accelerated sampling scheme that required half the scan time (eight vs. 16 heartbeats) but yielded equivalent results. The flexibility afforded by the improved imaging efficiency of MLLSR allows the acquisition to be tailored to particular clinical needs and to individual patient's breath-holding abilities.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Song T,Stainsby JA,Ho VB,Hood MN,Slavin GSdoi
10.1002/mrm.24137subject
Has Abstractpub_date
2012-03-01 00:00:00pages
622-7issue
3eissn
0740-3194issn
1522-2594journal_volume
67pub_type
杂志文章abstract::In several applications, MRI is used to monitor the time behavior of the signal in an organ of interest; e.g., signal evolution because of physiological motion, activation, or contrast-agent accumulation. Dynamic applications involve acquiring data in a k-t space, which contains both temporal and spatial information. ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1522-2594(199911)42:5<813::aid-mrm1>
更新日期:1999-11-01 00:00:00
abstract::When developing new techniques for NMR imaging and in vivo spectroscopy it is a major advantage to be able to calculate the magnetization slice profiles, at any point during a pulse sequence in the presence of a field gradient. While this has frequently been done by treating the problem as a number of discrete resonan...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910050511
更新日期:1987-11-01 00:00:00
abstract::The changes in the response of skeletal muscle to maximal dynamic exercise were investigated in going from a fasted state to a refed state by means of 31P NMR spectroscopy. It was found that in the fasted state, exercise-induced changes in Pi/PCr and in pH were both inhibited, in comparison with those in the refed sta...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910030616
更新日期:1986-12-01 00:00:00
abstract::An array of 33 prototype polypeptides was examined as putative contrast agents that can be distinguished from each other based on the chemical exchange saturation transfer (CEST) mechanism. These peptides were chosen based on predictions of the chemical exchange rates of exchangeable amide, amine, and hydroxyl protons...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21683
更新日期:2008-10-01 00:00:00
abstract:PURPOSE:To study the utility of fractional calculus in modeling gradient-recalled echo MRI signal decay in the normal human brain. METHODS:We solved analytically the extended time-fractional Bloch equations resulting in five model parameters, namely, the amplitude, relaxation rate, order of the time-fractional derivat...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26222
更新日期:2017-04-01 00:00:00
abstract:PURPOSE:In this study, an iterative k-t principal component analysis (PCA) algorithm with nonrigid frame-to-frame motion correction is proposed for dynamic contrast-enhanced three-dimensional perfusion imaging. METHODS:An iterative k-t PCA algorithm was implemented with regularization using training data corrected for...
journal_title:Magnetic resonance in medicine
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更新日期:2014-07-01 00:00:00
abstract:PURPOSE:The clinical potential of the diffusion imaging-based analysis of fine brain structures such as fornix or cingulum is high due to the central role of these structures in psychiatric diseases. However, the quantification of diffusion parameters in fine structures is especially prone to partial volume effects (PV...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24774
更新日期:2014-03-01 00:00:00
abstract::Acute normovolemic hemodilution (HD) was induced in anesthetized rats to assess the effect of changes in hematocrit (Hct) on signal intensity in T2*-weighted magnetic resonance (MR) images. Other relevant physiological parameters were maintained invariant. Two degrees of HD were induced: mild (Hct reduced from 42.6+/-...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910400611
更新日期:1998-12-01 00:00:00
abstract:PURPOSE:To develop and validate a method for acquiring helium-3 ((3) He) and proton ((1) H) three-dimensional (3D) image sets of the human lung with isotropic spatial resolution within a 10-s breath-hold by using compressed sensing (CS) acceleration, and to assess the fidelity of undersampled images compared with fully...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25499
更新日期:2015-10-01 00:00:00
abstract::The most widely-used functional magnetic resonance imaging (fMRI) technique is based on the blood oxygenation level dependent (BOLD) effect, which requires at least partial uncoupling between cerebral blood flow (CBF) and oxygen consumption changes during increased mental activity. To compare BOLD and CBF effects duri...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910380110
更新日期:1997-07-01 00:00:00
abstract::Signal-to-noise ratio (SNR) is a major challenge to sodium magnetic resonance imaging. Phased array coils have been shown significantly improving SNR in proton imaging over volume coils. This study investigates SNR advantage of a 15-channel array head coil (birdcage volume coil for transmit/receive and 15-channel arra...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24192
更新日期:2012-12-01 00:00:00
abstract::Human intervertebral discs were investigated by 1H NMR in vitro. The measured parameters of samples differently located in discs give the "maps" of discs. The spin-lattice relaxation-time maps show similar structure to dry matter and bound water maps, which might mean the future possibility to detect certain disc proc...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910030122
更新日期:1986-02-01 00:00:00
abstract::A study was made of the in vivo detectability of a pH-sensitive, imidazolidine spin probe, and the efficacy of low-frequency electron spin resonance (ESR)-based techniques for pH measurement in vitro and in vivo in rats. The techniques used were longitudinally-detected ESR (LODESR) and field-cycled dynamic nuclear pol...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10392
更新日期:2003-03-01 00:00:00
abstract::This paper describes a method for correcting the chemical-shift artifacts in 19F NMR imaging of perfluoroctylbromide emulsion (PFOB) by utilizing the two spectral peaks of PFOB which have a long T2 value in conjunction with the Dixon method. Corrected images are obtained from the magnitude of the measured images using...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910230206
更新日期:1992-02-01 00:00:00
abstract::Mumps virus-infected and normal newborn hamster brains were imaged with magnetic resonance (MR) within 24 h after birth and serially scanned. Hydrocephalus developed explosively on Day 6 postinfection and progressed until death occurred soon after Day 10. This study demonstrates the utility of MR in the investigation ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910040611
更新日期:1987-06-01 00:00:00
abstract::T1 is often ill-determined. This means that an Ernst angle excitation often cannot be precisely defined for the simple pulse and acquire experiment. Here, published 31P T1 values of metabolites in human muscle, liver, heart, and brain are archived, some new data on heart and brain added, and overall confidence interva...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910320120
更新日期:1994-07-01 00:00:00
abstract:PURPOSE:Recently, natural d-glucose was suggested as a potential biodegradable contrast agent. The feasibility of using d-glucose for dynamic perfusion imaging was explored to detect malignant brain tumors based on blood brain barrier breakdown. METHODS:Mice were inoculated orthotopically with human U87-EGFRvIII gliom...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25995
更新日期:2015-12-01 00:00:00
abstract::Longitudinal P-31 relaxation rate enhancements of phosphate groups have been measured at pH 7-7.2 and 310 degrees K on aqueous solutions containing adenosine triphosphate (ATP), phosphocreatine (PCr), inorganic phosphate (Pi) and some lanthanide complexes (Gd-DOTA, Gd-HPDO3A, Gd-DO3A, Gd-DTPA, Gd-DTPA-BMA). The macroc...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910310413
更新日期:1994-04-01 00:00:00
abstract::A simple and reliable method for quantifying the fluid content and characterizing the tissue T2 relaxation properties of animal extremities has been devised. This one-dimensional magnetic resonance imaging experiment, applied to the adjuvant arthritis model in rats, provides a useful, noninvasive monitor of the course...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910150208
更新日期:1990-08-01 00:00:00
abstract::In this work, substrate selection was monitored in the left ventricle of the canine myocardium by following pyruvate and lactate oxidation under in vivo conditions at basal and elevated workloads. These studies were conducted in the open chest model using dynamic 13C NMR techniques in the presence and absence of dichl...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910380608
更新日期:1997-12-01 00:00:00
abstract:PURPOSE:A ghost correction strategy for Simultaneous Multi-Slice (SMS) EPI methods that provides improved ghosting artifact reduction compared to conventional methods is presented. Conventional Nyquist ghost correction methods for SMS-EPI rely on navigator data that contain phase errors from all slices in the simultane...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27113
更新日期:2018-10-01 00:00:00
abstract:PURPOSE:To investigate the effect of realistic microstructural geometry on the susceptibility-weighted MR signal in white matter (WM), with application to demyelination. METHODS:Previous work has modeled susceptibility-weighted signals under the assumption that axons are cylindrical. In this study, we explored the imp...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26689
更新日期:2018-01-01 00:00:00
abstract:PURPOSE:Structure-guided total variation is a recently introduced prior that allows reconstruction of images using knowledge of the location and orientation of edges in a reference image. In this work, we demonstrate the advantages of a variant of structure-guided total variation known as directional total variation (D...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.28245
更新日期:2020-10-01 00:00:00
abstract:PURPOSE:As the premiere modality for brain imaging, MRI could find wider applicability if lightweight, portable systems were available for siting in unconventional locations such as intensive care units, physician offices, surgical suites, ambulances, emergency rooms, sports facilities, or rural healthcare sites. METH...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25147
更新日期:2015-02-01 00:00:00
abstract::An eight-channel receive-only brain coil and table-top detunable volume transmit coil were developed and tested at 7 T for human imaging. Optimization of this device required attention to sources of interaction between the array elements, between the transmit and receive coils and minimization of common mode currents ...
journal_title:Magnetic resonance in medicine
pub_type: 临床试验,杂志文章
doi:10.1002/mrm.20547
更新日期:2005-07-01 00:00:00
abstract:PURPOSE:Myocardial blood-flow simulation based on laws of fluid mechanics is a valuable tool for understanding tissue behavior. Our aim is to evaluate the ability of a porous-media flow model approach to reflect disturbed washout of contrast media (CM) from the myocardium as observed by cardiovascular MR. METHODS:A co...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27756
更新日期:2019-08-01 00:00:00
abstract:PURPOSE:Previous work has evaluated the quality of different analytic methods for extracting relaxation times from magnitude imaging data exhibiting Rician noise. However, biexponential analysis of relaxation in tissue, including cartilage, and materials is of increasing interest. We, therefore, analyzed biexponential ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25111
更新日期:2015-01-01 00:00:00
abstract:PURPOSE:The purpose of this study is to increase the robustness of MR fingerprinting (MRF) toward subject motion. METHODS:A novel reconstruction algorithm, MOtion insensitive MRF (MORF), was developed, which uses an iterative reconstruction based retrospective motion correction approach. Each iteration loops through t...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27227
更新日期:2018-12-01 00:00:00
abstract::Formalin fixation of tissue is a common laboratory practice. A direct comparison of diffusion tensor imaging (DTI) parameters from mouse brains before (in vivo) and after (ex vivo) formalin fixation is reported herein. Five diffusion indices were examined in a cohort of seven mice: relative anisotropy (RA), directiona...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10605
更新日期:2003-10-01 00:00:00
abstract:PURPOSE:To exploit the improved comparability and hardware independency of quantitative MRI, databases of MR physical parameters in healthy tissue are required, to which tissue properties of patients can be compared. In this work, normative values for longitudinal and transverse relaxation times in the brain were estab...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27927
更新日期:2020-01-01 00:00:00