Echo-spacing optimization for the simultaneous measurement of reversible (R2′) and irreversible (R2) transverse relaxation rates
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چکیده
منابع مشابه
Differentiating haematoma with the R2' relaxation rate
Introduction Subdural haematoma (SDH) is a form of traumatic brain injury that can be classified as acute, subacute or chronic, based upon time from injury. When acute, it is a medical emergency in which surgical decompression is the only option to prevent mortality. Small subdurals and those that are no longer actively bleeding may be left to re-absorb spontaneously and clinical decision-makin...
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OBJECTIVE To explore the transverse relaxation rate with gradient echo R2(*) changes in patients with Parkinsonian variant of multiple system atrophy (MSA-P) with a voxel-based analysis of R2(*) map. METHODS Whole brain structural images and multi-echo T2(*) weighted image were acquired in 27 patients with probable MSA-P and 24 healthy individuals. R2(*) maps of the MSA-P were compared with t...
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Relaxation rates provide important information about tissue microstructure. Multi-parameter mapping (MPM) estimates multiple relaxation parameters from multi-echo FLASH acquisitions with different basic contrasts, i.e., proton density (PD), T1 or magnetization transfer (MT) weighting. Motion can particularly affect maps of the apparent transverse relaxation rate R2(*), which are derived from th...
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Introduction: The effective rate of decay of transverse magnetization, R2* = 1/T2*, is sensitive to B0 distortions at a mesoscopic scale (1). It is thus highly correlated to tissue concentrations of non-heme iron (2) and myelinated axons (3), especially at high and ultra-high field strengths (2-4). R2* is commonly measured using long-TR multi-slice gradient echo sequences. This approach implies...
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Introduction There is increased interest in a combined acquisition of gradient-echo (GE) and spin-echo (SE) signals for applications in DSC-PWI and fMRI. One of the main reasons is the different sensitivity of GEs and SEs to different compartments of the underlying microvasculature. While GEs are sensitive to both static and dynamic dephasing of spins, SEs are sensitive to dynamic spin dephasin...
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ژورنال
عنوان ژورنال: Magnetic Resonance Imaging
سال: 2007
ISSN: 0730-725X
DOI: 10.1016/j.mri.2006.09.008