[Image Quality of the Pancreas Using Readout-segmented Echo-planar Imaging]

To evaluate the usefulness of readout-segmented echo-planar imaging (RS-EPI) compared with single-shot EPI (SS-EPI) in diffusion-weighted imaging (DWI) of the pancreas.

Fourteen healthy volunteers underwent pancreatic DWI using both SS-EPI and RS-EPI. The depiction area of the pancreas, signal-to-noise ratio (SNR), sharpness, apparent diffusion coefficient (ADC) values, and acquisition time were compared. The depiction area was normalized using half-Fourier acquisition single-shot turbo spin echo (HASTE) images. SNR was calculated using the identical region of interest method, and sharpness was derived from the signal intensity profile.

The depiction area was 0.84±0.11 with SS-EPI and 0.97±0.11 with RS-EPI (P<0.05). The SNR values in the pancreatic head were 22.0±11.0 and 12.4±4.2 (P<0.05), in the pancreatic body 19.0±6.9 and 11.1±3.0 (P<0.05), and in the pancreatic tail 19.8±9.0 and 14.7±5.6 (P=0.08), respectively. Sharpness was 0.36±0.11 and 0.33±0.06 in the head (P=0.36), 0.37±0.07 and 0.41±0.11 in the body (P=0.28), and 0.36±0.07 and 0.32±0.08 in the tail (P=0.18), respectively. The ADC values were (1.11±0.11)×10^-3 mm²/s and (1.24±0.16)×10^-3 mm²/s in the head (P<0.05), (1.28±0.15)×10^-3 mm²/s and (1.20±0.13)×10^-3 mm²/s in the body (P=0.19), and (1.08±0.11)×10^-3 mm²/s and (1.16±0.18)×10^-3 mm²/s in the tail (P=0.14), respectively. The acquisition time for SS-EPI was 298±45 s, whereas RS-EPI had a fixed acquisition time.

For pancreatic DWI, RS-EPI reduces distortion compared with SS-EPI, resulting in a larger depiction area. While maintaining sharpness and ADC values with a fixed acquisition time, RS-EPI serves as a useful imaging technique.