Standardization of the apparent diffusion coefficient value of bladder cancer across different centers: Applicability in predicting aggressive pathologic phenotypes

Abstract Purpose We investigated whether the standardized apparent diffusion coefficient (ADC) value reflects bladder cancer characteristics across different centers. Methods Ninety-eight bladder cancer patients underwent MRI at two institutions. Standardized tumor ADC (sT-ADC) was calculated by dividing absolute tumor ADC (aT-ADC) by that of gluteus maximus. We compared ADCs between MRI protocols according to grade and T-stage. Results The differences in aT-ADC between MRI protocols were negated by sT-ADC. The best sT-ADC cut-offs to predict cancer aggressiveness in the development cohort worked in the validation cohort compared to the development cohort. Conclusion Standardized ADC overcomes the incompatibility between different MRI protocols.