In:
Magnetic Resonance in Medicine, Wiley, Vol. 74, No. 2 ( 2015-08), p. 474-481
Abstract:
To study temporal and spatial blurring artifacts from k‐space view‐sharing in time‐resolved MR angiography (MRA) and to propose a technique for reducing these artifacts. Methods We acquired k‐space data sets using a three‐dimensional time‐resolved MRA view‐sharing sequence and retrospectively reformatted them into two reconstruction frameworks: full view‐sharing via time‐resolved imaging with stochastic trajectories (TWIST) and minimal k‐space view‐sharing and compressed sensing (CS‐TWIST). The two imaging series differed in temporal footprint but not in temporal frame rate. The artifacts from view‐sharing were compared qualitatively and quantitatively in nine patients in addition to a phantom experiment. Results CS‐TWIST was able to reduce the imaging temporal footprint by two‐ to three‐fold compared with TWIST, and the overall subjective image quality of CS‐TWIST was higher than that for TWIST ( P 〈 0.05). View sharing caused a delay in the visualization of small blood vessels, and the mean transit time of the carotid artery calculated based on TWIST reconstruction was 0.6 s longer than that for CS‐TWIST ( P 〈 0.01). In thoracic MRA, the shorter temporal footprint decreased the sensitivity to physiological motion blurring, and vessel sharpness was improved by 8.8% ± 6.0% using CS‐TWIST ( P 〈 0.05). Conclusion In time‐resolved MRA, the longer temporal footprint due to view‐sharing causes spatial and temporal artifacts. CS‐TWIST is a promising method for reducing these artifacts. Magn Reson Med 74:474–481, 2015. © 2014 Wiley Periodicals, Inc.
Type of Medium:
Online Resource
ISSN:
0740-3194
,
1522-2594
Language:
English
Publisher:
Wiley
Publication Date:
2015
detail.hit.zdb_id:
1493786-4
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