Abstract:
:This study characterizes gains in sensitivity and spectral resolution of proton echo-planar spectroscopic imaging (PEPSI) with increasing magnetic field strength (B(0)). Signal-to-noise ratio (SNR) per unit volume and unit time, and intrinsic linewidth (LW) of N-acetyl-aspartate (NAA), creatine (Cr), and choline (Cho) were measured with PEPSI at 1.5, 3, 4, and 7 Tesla on scanners that shared a similar software and hardware platform, using circularly polarized (CP) and eight-channel phased-array (PA) head coils. Data were corrected for relaxation effects and processed with a time-domain matched filter (MF) adapted to each B(0). The SNR and LW measured with PEPSI were very similar to those measured with conventional point-resolved spectroscopy (PRESS) SI. Measurements with the CP coil demonstrated a nearly linear SNR gain with respect to B(0) in central brain regions. For the PA coil, the SNR-B(0) relationship was less than linear, but there was a substantial SNR increase in comparison to the CP coil. The LW in units of ppm decreased with B(0), resulting in improved spectral resolution. These studies using PEPSI demonstrated linear gains in SNR with respect to B(0), consistent with theoretical expectations, and a decrease in ppm LW with increasing B(0).
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Otazo R,Mueller B,Ugurbil K,Wald L,Posse Sdoi
10.1002/mrm.21067subject
Has Abstractpub_date
2006-12-01 00:00:00pages
1200-10issue
6eissn
0740-3194issn
1522-2594journal_volume
56pub_type
杂志文章abstract::In the ongoing quest for faster imaging and higher spatial resolution, several methods have been developed to speed up data acquisition by incorporating prior information about the object being imaged. This study shows that many of these methods can be integrated into a single common equation. The unified framework pr...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1242
更新日期:2001-10-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:2010-01-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26730
更新日期:2018-02-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.23041
更新日期:2012-03-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.23105
更新日期:2012-05-01 00:00:00
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journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.1910300115
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:2012-01-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26896
更新日期:2018-05-01 00:00:00
abstract:PURPOSE:To develop a rapid imaging framework for balanced steady-state free precession (bSSFP) that jointly reconstructs undersampled data (by a factor of R) across multiple coils (D) and multiple acquisitions (N). To devise a multi-acquisition coil compression technique for improved computational efficiency. METHODS:...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26902
更新日期:2018-05-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910200207
更新日期:1991-08-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1522-2594(199901)41:1<132::aid-mrm18
更新日期:1999-01-01 00:00:00
abstract:PURPOSE:In conventional three-dimensional magnetic resonance elastography, motion encoding gradients (MEGs) synchronized to a mechanical excitation are applied separately in each direction to encode tissue displacement generated by the corresponding waves. This requires long acquisition times that introduce errors due ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25280
更新日期:2015-04-01 00:00:00
abstract::The complexity of biologic tissues, with multiple compartments each with its own diffusion and relaxation properties, requires complex formalisms to model water signal in most magnetic resonance imaging or magnetic resonance spectroscopy experiments. In this article, we describe a magnetic susceptibility-induced shift...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20565
更新日期:2005-07-01 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::High-signal artifacts produced by cerebrospinal fluid (CSF) flow can adversely affect fluid-attenuated inversion recovery (FLAIR) imaging of the brain and spinal cord. This study explores the use of a nonslice-selective inversion pulse to eliminate CSF flow artifacts together with a technique called "K-space Reordered...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1198
更新日期:2001-08-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20896
更新日期:2006-06-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20910
更新日期:2006-06-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10204
更新日期:2002-08-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 临床试验,杂志文章
doi:10.1002/mrm.20627
更新日期:2005-10-01 00:00:00
abstract::This report describes a noninvasive 1H-NMR method for measuring absolute temperatures (+/- 0.2 degrees C) in biological samples and, in particular, in cell culture perfusion systems, utilizing the linear temperature dependence of the water chemical shift relative to the temperature-independent shift of one of the comp...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910290120
更新日期:1993-01-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20767
更新日期:2006-02-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26028
更新日期:2016-11-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22413
更新日期:2010-06-01 00:00:00
abstract::Cortical bone in the mature skeleton has a short T(2)* and produces no detectable signal with conventional MR sequences. A two-dimensional ultrashort echo time (UTE) sequence employing half radio frequency (RF) pulse excitations and radial ramp sampling reduces the effective TE to 8 micros and is capable of detecting ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21397
更新日期:2007-11-01 00:00:00
abstract::Radiofrequency induced pacemaker lead tip heating is one of the main reasons magnetic resonance imaging (MRI) is contraindicated for patients with pacemakers. The objective of this work was to evaluate the dependence of pacemaker lead tip heating during MRI scanning on the electrical conductivity of the medium surroun...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.23235
更新日期:2012-08-01 00:00:00
abstract::A magnetic resonance imaging (MRI) method is presented to detect, localize, and quantify myocardial kinematics by measuring the material rate-of-strain tensor at each pixel in gated NMR images of the heart. The immediate, local effect of muscular activity is self-deformation, and the strain tensor is the basic mathema...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910270107
更新日期:1992-09-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22899
更新日期:2011-11-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24958
更新日期:2014-09-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27590
更新日期:2019-04-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:2000-03-01 00:00:00