Diffusion-weighted MRI for differential diagnosis in gallbladder lesions with special reference to ADC cut-off values

We retrospectively evaluated the usefulness of the apparent diffusion coefficient (ADC) measured from high-b value diffusion-weighted imaging (DWI) of magnetic resonance imaging for the differential diagnosis of gallbladder lesions among patients with cancer, adenoma and inflammatory disease.

Forty patients with gallbladder lesions (22 patients with cancer, 7 patients with adenoma, and 11 patients with inflammatory disease) were enrolled in this study. All patients underwent high-b value DWI, and the ADC value was measured. The cut-off values were determined by receiver operating characteristic analysis.

The ADC values of gallbladder cancers (1.31±0.57x10-3 mm2/s) were smallest and those of adenomas (2.66±0.43x10-3 mm2/s) were largest among the diseases. Inflammatory diseases took a middle position (1.97±0.54x10-3 mm2/s) between them. There were significant differences among the 3 groups of diseases (p<0.05). The cut-off value within ADC values to discriminate cancer from the other diseases was 1.64x10-3 mm2/s (accuracy 87.5%), and that to discriminate adenoma was 2.25x10-3 mm2/s (accuracy 90.0%).

The ADC values measured from high-b value DWI would be useful for the differential diagnosis of gallbladder lesions.