Parallel imaging-based reduction of acoustic noise for clinical magnetic resonance imaging

摘要

OBJECTIVES: The objective of this study was to demonstrate the feasibility of improving perceived acoustic comfort for a standard clinical magnetic resonance imaging protocol via gradient wave form optimization and validate parallel imaging as a means to achieve a further reduction of acoustic noise. MATERIALS AND METHODS: The gradient wave forms of a standard T2 axial turbo spin-echo (TSE) sequence in head examinations were modified for acoustic performance while attempting to keep the total acquisition and inter-echo spacing the same. Parallel imaging was then used to double the inter-echo spacing and allow further wave form optimization. Along with comparative acoustic noise measurements, a statistical analysis of radiologist scoring was conducted on volumes from standard and modified sequences acquired from 10 patients after informed consent was obtained. RESULTS: Compared with TSE, significant improvement of acoustic comfort was measured for modified-sequences quiet TSE and quiet TSE with generalized autocalibrating partially parallel acquisitions (P = 0.0034 and P = 0.0003, respectively), and no statistically significant difference in diagnostic quality was observed without the use of parallel imaging. CONCLUSIONS: Standard clinical magnetic resonance imaging protocols can be made quieter through adequate gradient wave form optimization. In scans with high signal-to-noise ratio, parallel imaging can be used to further reduce acoustic noise.