Strategies to improve contrast in turboFLASH imaging: Reordered phase encoding and K‐space segmentation
作者:
Daisy Chien,
Dennis J. Atkinson,
Robert R. Edelman,
期刊:
Journal of Magnetic Resonance Imaging
(WILEY Available online 1991)
卷期:
Volume 1,
issue 1
页码: 63-70
ISSN:1053-1807
年代: 1991
DOI:10.1002/jmri.1880010108
出版商: Wiley Subscription Services, Inc., A Wiley Company
关键词: Artifact;Liver, MR studies, 761.1214;Liver neoplasms, MR studies, 761.3;Phantoms;Physics;Pulse sequences;Rapid imaging
数据来源: WILEY
摘要:
AbstractTurboFLASH (fast low‐angle shot) sequences enable the acquisition of an image in a fraction of a second. However, unique to T1‐weighted ultra‐fast imaging, the magnetization variation during image acquisition can produce artifacts along the phase‐encoding direction. In this study, the signal behavior and nature of these artifacts were analyzed with various acquisition schemes to improve image contrast. The magnetization variation during image acquisition and its filtering effect on the image were simulated for three different approaches to T1‐weighted turboFLASH imaging: standard turboFLASH with (a) mono‐tonically ascending phase‐encoding steps, (b) reordered phase encoding, and (c) k‐space segmentation. Each of the modified data acquisition schemes has advantages. However, for sub‐second imaging, reordered phase encoding produced improved image contrast over that of standard turboFLASH, and segmented k‐space imaging gave superior tissue contrast compared with that of both standard and reordered turboFLASH, with imaging time that permits
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