Diffusion-weighted MR imaging with single-shot echo-planar imaging in the upper abdomen: preliminary clinical experience in 61 patients

Background: To determine the potential ability of diffusion-weighted magnetic resonance (MR) imaging with single-shot echo-planar imaging (DW imaging) in the upper abdomen by apparent diffusion coefficient (ADC) and signal:intensity ratio (SIR) measurements. Methods: DW imaging was performed in 61 clinical patients. ADCs in the liver, pancreas, spleen, kidney, and different pathological conditions were calculated. Spleen-to-liver SIR and segmental intensity difference of the liver (SID) were also calculated. Results: The mean ADCs (mm(2)/s) were 2.28 x 10(-3) +/- 0.07 in the liver, 1.44 x 10(-3) +/- 0.05 in the spleen, 1.94 x 10(-3) +/- 0.19 in the pancreas, and 5.76 x 10(-3) +/- 0.06 in the kidney. The mean ADC of cirrhotic liver was 1.96 x 10(-3) +/- 0.62, which was lower than that of normal liver. Other pathologic conditions also showed ADCs different from those of normal tissues. All DW images showed significantly higher spleen-to-liver SIRs and SIDs than did T2-weighted images (p < 0.05). Conclusion: The mean ADCs obtained with DW imaging were different in each upper abdominal organ and with each pathologic condition. DW images showed: better soft tissue contrast than did T2-weighted images with regard to SIR and CNR in depicting and characterizing upper abdominal disorders.