Functional MRI using multiple receiver coils: BOLD signal changes and signal-to-noise ratio for three-dimensional-PRESTO vs. single shot EPI in comparison to a standard quadrature head coil.

摘要

PURPOSE: To compare the performance of single shot echo planar imaging (SSEPI) with three-dimensional-multishot echo-planar imaging (EPI) based on principles-of-echo-shifting-with-a-train-of-observations (PRESTO) in combination with a standard quadrature head coil and, as an alternative, a multiple receiver coil in intraoperative functional magnetic resonance imaging (fMRI). MATERIALS AND METHODS: Six healthy subjects underwent fMRI with visual stimulation using a SSEPI and a PRESTO-sequence with both coil systems. Statistical evaluation was done with a scanner-based post-processing software and SPM 99. The number of activated voxels in the visual cortex, the percent signal change between rest and activation, and finally the signal-to-noise ratio (SNR) during time course were measured and compared for both coil systems and both sequences, used in four different combinations. RESULTS: Blood oxygen level dependent (BOLD) signal changes were the lowest with PRESTO and standard head coil and the highest for SSEPI and phased array coil. For the latter combination, a significantly higher signal change and larger activation size was observed together with a better SNR. SSEPI yielded similar performance using both coils. CONCLUSION: SSEPI was superior due to its better SNR and a higher BOLD signal change in the defined settings, irrespective of the coil used. In a stereotactical setup the phased array coil can be used to generate fMRI data without loss of image quality.