Myocardial T 2 mapping with respiratory navigator and automatic nonrigid motion correction

Autor: Orlando P. Simonetti, Yiu-Cho Chung, Saurabh Shah, Michael L. Pennell, Jens Guehring, Hui Xue, Sven Zuehlsdorff, Subha V. Raman, Shivraman Giri
Rok vydání: 2012
Předmět:
Zdroj: Magnetic Resonance in Medicine. 68:1570-1578
ISSN: 0740-3194
DOI: 10.1002/mrm.24139
Popis: Quantitative T₂ mapping was recently shown to be superior to T₂-weighted imaging in detecting T₂ changes across myocardium. Pixel-wise T₂ mapping is sensitive to misregistration between the images used to generate the parameter map. In this study, utility of two motion-compensation strategies-(i) navigator gating with prospective slice correction and (ii) nonrigid registration-was investigated for myocardial T₂ mapping in short axis and horizontal long axis views. Navigator gating provides respiratory motion compensation, whereas registration corrects for residual cardiac and respiratory motion between images; thus, the two strategies provided complementary functions. When these were combined, respiratory-motion-induced T₂ variability, as measured by both standard deviation and interquartile range, was comparable to that in breath-hold T₂ maps. In normal subjects, this combined motion-compensation strategy increased the percentage of myocardium with T₂ measured to be within normal range from 60.1% to 92.2% in short axis and 62.3% to 92.7% in horizontal long axis. The new motion-compensated T₂ mapping technique, which combines navigator gating, prospective slice correction, and nonrigid registration to provide through-plane and in-plane motion correction, enables a method for fully automatic and robust free-breathing T₂ mapping.
Databáze: OpenAIRE
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