• diffusion-weighted imaging
• magnetic resonace imaging
• pancreas
• reduced field of view
• solid lesions

Purpose: To compare image quality, presence of artifacts and apparent diffusion coefficient (ADC) values between reduced field-of-view (FOV) and large FOV single-shot (SS) echo-planar imaging (EPI) diffusion-weighted imaging (DWI).
Materials and methods: From our radiological database we retrospectively selected 3T MR examinations (GE Discovery MR750; GE Healthcare) of 60 patients with solid pancreatic lesions. Two readers independently performed qualitative analysis and calculated by consensus quantitative ADC values of solid pancreatic lesions in both large FOV and reduced FOV DWI. The qualitative analysis parameters included: 1) Sharpness, 2) Distortion, Ghosting, Motion and Susceptibility artifacts, 3) Lesion Conspicuity and 4) Overall Image Quality. These parameters were evaluated using a 4-point scale. T-test for paired data was used to compare qualitative scores and ADC values between large FOV and reduced FOV DWI, as well as to assess inter-reader agreement.
Results: On qualitative analysis, the scores of reduced FOV DWI were better for sharpness (2.68 ± 0.71), artifacts (2.62 ± 0.71) and overall image quality (2.82 ±0.73) as compared to large FOV DWI (sharpness, 2.45 ± 0.55; artifacts, 2.42 ± 0.58; overall image quality, 2.59 ± 0.56) (p < 0.05). No significant difference was found for lesion conspicuity (2.89 ± 0.85 at reduced FOV and 2.78 ± 0.90 at large FOV DWI) (p > 0.05). On quantitative analysis, there was no significant difference between the two sequences in ADC values of various solid pancreatic lesions (p > 0.05).
Conclusions: Reduced FOV DWI of the pancreas provides better anatomic structure visualization, reduced artifacts and better overall image quality as compared to large FOV DWI. ADC values were not significantly different between the two sequences. Reduced FOV DWI could be included in the standard MRI protocol of the pancreas.