Abstract：
:Relaxation times estimation methods play a central role in various problems, such as magnetic resonance (MR) hardware calibration, tissue characterization, or temperature measurement. Previous studies have proposed optimization criteria to estimate the relaxation time T1 faster than with a multipoint method leading to two-point methods. In this paper, the class of optimized two-point methods is extended to gradient-echo (GE) sequence offering new advantages over spin-echo (SE) or inversion recovery (IR) sequences. Two GE acquisitions, with optimal flip angles theta1 and theta2 minimizing both the total scan time and the variance in the computed T1 image were applied to estimate T1, and the results were compared with those of SE sequence with optimized paired repetition times T(R1) and T(R2). First, phantom studies were carried out with five tissue-like samples on a 0.5T scanner. Then in vivo, human brain T1 image were calculated using both optimized GE and SE two-point methods. More precise T1 GE estimates than those for SE were found thanks to high signal-to-noise ratio (SNR) per unit of time, but with a small bias. These results also concern the temperature variation measurement methods, based on T1 estimation. Preliminary experimental data for temperature measurement are given.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
Imran J,Langevin F,Saint-Jalmes Hdoi
10.1016/s0730-725x(99)00092-2subject
Has Abstractpub_date
1999-11-01 00:00:00pages
1347-56issue
9eissn
0730-725Xissn
1873-5894pii
S0730-725X(99)00092-2journal_volume
17pub_type
杂志文章abstract：:Diffusion tensor imaging (DTI) constitutes the most used paradigm among the diffusion-weighted magnetic resonance imaging (DW-MRI) techniques due to its simplicity and application potential. Recently, real-time estimation in DW-MRI has deserved special attention, with several proposals aiming at the estimation of mean...
journal_title：Magnetic resonance imaging
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(90)90101-7
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journal_title：Magnetic resonance imaging
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2016.10.013
更新日期：2017-04-01 00:00:00
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(90)90019-x
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章,评审
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2015.06.017
更新日期：2015-11-01 00:00:00
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(95)00010-e
更新日期：1995-01-01 00:00:00
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(97)00251-8
更新日期：1998-01-01 00:00:00
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2020.07.008
更新日期：2020-11-01 00:00:00
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(96)00172-5
更新日期：1996-01-01 00:00:00
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(89)90325-1
更新日期：1989-01-01 00:00:00
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(94)92198-9
更新日期：1994-01-01 00:00:00
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2015.12.024
更新日期：2016-05-01 00:00:00
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
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更新日期：2013-01-01 00:00:00
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journal_title：Magnetic resonance imaging
pub_type： 临床试验,杂志文章,随机对照试验
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更新日期：1998-12-01 00:00:00
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
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更新日期：2019-06-01 00:00:00
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2007.07.003
更新日期：2008-02-01 00:00:00
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2004.01.029
更新日期：2004-06-01 00:00:00
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2012.06.014
更新日期：2013-02-01 00:00:00
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2008.02.006
更新日期：2008-11-01 00:00:00
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journal_title：Magnetic resonance imaging
pub_type： 临床试验,杂志文章
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更新日期：2000-04-01 00:00:00
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journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(89)90538-9
更新日期：1989-11-01 00:00:00
abstract：:Magnetic resonance imaging (MRI) and localized proton MR spectroscopy (MRS) techniques have been applied for studying different maturation processes in the histochemistry of coconut (Cocos nucifera). Images of the tender and mature coconut are characterized by protons of the aqueous solution present in the cavity and ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(95)00033-d
更新日期：1995-01-01 00:00:00
