In:
Magnetic Resonance in Medicine, Wiley, Vol. 80, No. 3 ( 2018-09), p. 1061-1073
Abstract:
This study introduces a highly accelerated whole‐brain direct visualization of short transverse relaxation time component (ViSTa) imaging using a wave controlled aliasing in parallel imaging (CAIPI) technique, for acquisition within a clinically acceptable scan time, with the preservation of high image quality and sufficient spatial resolution, and reduced residual point spread function artifacts. Methods Double inversion RF pulses were applied to preserve the signal from short T 1 components for directly extracting myelin water signal in ViSTa imaging. A 2D simultaneous multislice and a 3D acquisition of ViSTa images incorporating wave‐encoding were used for data acquisition. Improvements brought by a zero‐padding method in wave‐CAIPI reconstruction were also investigated. Results The zero‐padding method in wave‐CAIPI reconstruction reduced the root‐mean‐square errors between the wave‐encoded and Cartesian gradient echoes for all wave gradient configurations in simulation, and reduced the side‐main lobe intensity ratio from 34.5 to 16% in the thin‐slab in vivo ViSTa images. In a 4 × acceleration simultaneous‐multislice scenario, wave‐CAIPI ViSTa achieved negligible g‐factors (g mean /g max = 1.03/1.10), while retaining minimal interslice artifacts. An 8 × accelerated acquisition of 3D wave‐CAIPI ViSTa imaging covering the whole brain with 1.1 × 1.1 × 3 mm 3 voxel size was achieved within 15 minutes, and only incurred a small g‐factor penalty (g mean /g max = 1.05/1.16). Conclusion Whole‐brain ViSTa images were obtained within 15 minutes with negligible g‐factor penalty by using wave‐CAIPI acquisition and zero‐padding reconstruction. The proposed zero‐padding method was shown to be effective in reducing residual point spread function for wave‐encoded images, particularly for ViSTa.
Type of Medium:
Online Resource
ISSN:
0740-3194
,
1522-2594
Language:
English
Publisher:
Wiley
Publication Date:
2018
detail.hit.zdb_id:
1493786-4
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