Accelerated human cardiac diffusion tensor imaging using simultaneous multislice imaging.

Journal article

PURPOSE: To demonstrate the feasibility of accelerating measurements of cardiac fiber structure using simultaneous multislice (SMS) imaging. METHODS: SMS excitation with a blipped controlled aliasing (CAIPI) readout was incorporated into a diffusion-encoded stimulated echo pulse sequence to obtain diffusion measurements in three separate slices of the heart (8-mm thickness, 12-mm gap). A novel image entropy-based method for removing image ghosts in blipped CAIPI acquisitions is also introduced that enables SMS imaging of closely spaced slices in the heart. RESULTS: The average retained signal-to-noise ratio (SNR) using this acquisition scheme is 70% ± 5%, higher than the standard 1/3 = 57% SNR penalty with three-fold acceleration. No significant difference was observed in the apparent diffusion coefficient and helix angle diffusion parameters between a time-equivalent conventional single-slice scan and the three-fold accelerated SMS acquisition. A 10% mean bias was observed in fractional anisotropy between single-slice and SMS acquisitions. CONCLUSION: The new sequence was used to obtain high-quality diffusion measurements in three closely spaced cardiac slices in a clinically feasible nine breath-hold examination. The accelerated multiband sequence is anticipated to improve quantitative measurements of cardiac microstructure by reducing the number of breath-holds required for the scan, making it practical to incorporate diffusion tensor measurements within a comprehensive clinical examination. Magn Reson Med, 2014. © 2014 Wiley Periodicals, Inc.

Authors: Lau, A; Tunnicliffe, E; Frost, R; Koopmans, P; Tyler, D

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Magnetic Resonance in Medicine
• Volume: 73
• Issue: 3
• Pages: 995–1004
• Publication date: 2015-03-01
• DOI: 10.1002/mrm.25200
• EISSN: 1522-2594
• ISSN: 0740-3194
• Language: English
• Keywords: multiband; simultaneous multislice; blipped CAIPI; diffusion; parallel imaging; cardiac