Comparison of an 8-Channel with a 32-Channel Head Coil at 3 Tesla Based on Diffusion-Weighted Imaging with Various b-values: An ACR Phantom Study

The purpose of this study was to compare the effect of 8-channel and 32-channel head coils for 3 Tesla brain single shot spin echo diffusion-weighted imaging (DWI) with different b-values. All experiments were performed on a 3 Tesla magnetic resonance scanner using an 8-channel and a 32-channel head coils. The signal-tonoise ratio (SNR), apparent diffusion coefficient (ADC) values, and image distortions were measured with an American College of Radiology (ACR) head phantom. The SNR and ADC values decreased with increasing bvalue, and the distortion and image noise increased. In particular, DWI with a b-value >= 2000 showed significant noise and distortion for both coils. In conclusion, the use of 32-channel head coils has advantage for brain DWI compared with 8-channel head coils. However, brain DWI with a b-value >= 2000 did not statistically improve SNR on 32-channel coils compared with 8-channel coils, and showed a significant noise and distortion for both coils