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Free‐breathing slice‐interleaved myocardial T 2 mapping with slice‐selective T 2 magnetization preparation
Author(s) -
Basha Tamer A.,
Bellm Steven,
Roujol Sébastien,
Kato Shingo,
Nezafat Reza
Publication year - 2016
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.25907
Subject(s) - reproducibility , sequence (biology) , wafer , nuclear medicine , biomedical engineering , materials science , computer science , nuclear magnetic resonance , mathematics , medicine , physics , chemistry , biochemistry , statistics , nanotechnology
Purpose To develop and evaluate a free‐breathing slice‐interleaved T 2 mapping sequence by proposing a new slice‐selective T 2 magnetization preparation (T 2 prep) sequence that allows interleaved data acquisition for different slices in subsequent heartbeats. Methods We developed a slice‐selective T 2 prep for myocardial T 2 mapping by adding slice‐selective gradients to a conventional single‐slice T 2 prep sequence. In this sequence, five slices are acquired during five consecutive heartbeats, each using a slice‐selective T 2 prep. The scheme was repeated four times using different T 2 prep echo times. We compared the performance of the proposed slice‐interleaved T 2 mapping sequence and the conventional single‐slice T 2 mapping sequence in term of accuracy, precision, and reproducibility using phantom experiments and in vivo imaging in 10 healthy subjects. We also evaluated the feasibility of the proposed sequence in 28 patients with cardiovascular disease, and the quality of the maps was scored subjectively. Furthermore, we investigated the impact of through‐plane motion by comparing T 2 measurements acquired during end‐systole versus mid‐diastole. Results T 2 measurements using a slice‐interleaved T 2 mapping sequence were correlated with a spin echo (r 2 = 0.88) and single‐slice T 2 mapping sequence (r 2 = 0.98). The mean myocardial T 2 values were correlated between slice‐interleaved (48 ms) and single‐slice (51 ms) T 2 mapping sequences. Subjective scores of T 2 map quality were good to excellent in 81% of the maps in patients. There was no difference in T 2 measurements between end‐systole versus mid‐diastole. Conclusions The proposed free‐breathing slice‐interleaved T 2 mapping sequence allows T 2 measurements of five left ventricular slices in 20 heartbeats with similar reproducibility and precision as the single‐slice T 2 mapping sequence but with a four‐fold reduction in acquisition time. Magn Reson Med 76:555–565, 2016. © 2015 Wiley Periodicals, Inc.