Gallbladder carcinoma: an initial clinical experience of reduced field-of-view diffusion-weighted MRI

Background The purpose of this study is to compare the diagnostic value, imaging quality and apparent diffusion coefficient (ADC) value of reduced field-of-view diffusion-weight imaging (r-FOV DWI) and full field-of-view diffusion-weight imaging (f-FOV DWI) in patients with gallbladder carcinoma and other lesions of gallbladder. Methods Two hundred ninety-six patients with gallbladder diseases underwent both r-FOV DWI and f-FOV DWI on a 3.0 T MRI scanner. Two radiologists assessed subjective image quality parameters independently. The Wilcoxon signed-rank test was used to compare subjective qualitative image score. Objective quality values and the mean ADC values were analyzed by pairedt-test. The correlation between pathological results and mean ADC value were estimated using Spearman rank correlation analysis. Results The CNR value (10.23 +/- 2.92) and image quality score (13.84 +/- 1.07) of r-FOV DWI were significantly higher than those of f-FOV DWI (5.24 +/- 1.29P<0.001; 10.41 +/- 1.11 P<0.001). There was no significant difference between mean ADC values of the two DWI sequences for all three groups (Group 1, chronic cholecystitis; Group 2, benign lesions of gallbladder; Group 3, gallbladder carcinoma.P = 0.239, 0.974 and 0.226 respectively). For both DWI sequences, the mean ADC values were the highest in the group of cholecystitis and the lowest in the group of gallbladder carcinoma (2.49 +/- 0.14 vs 1.49 +/- 0.12; 2.50 +/- 0.14 vs 1.50 +/- 0.13, for f-FOV and r-FOV respectively), the differences among groups were statistically significant (P<0.01). The mean ADC values for both DWI sequences were negatively correlated with the group number, which increased with the malignant tendency of lesions (r = - 0.892, P<0.01; r = - 0.913, P<0.01 for f-FOV and r-FOV respectively). Conclusion Reduced Field-of-view Diffusion-weighted MRI is a good tool to diagnosis the gallbladder carcinoma, with better image quality and without affecting ADC values.