Prediction of muscle invasion of bladder cancer: A comparison between DKI and conventional DWI.

OBJECTIVES

To prospectively compare the diagnostic efficacy of conventional diffusion-weighted imaging (DWI) and diffusion kurtosis imaging (DKI) in differentiating between muscle-invasive bladder cancer (MIBC) and non-muscle-invasive bladder cancer (NMIBC).

METHODS

Multiple b value DWIs were performed using a 3-T magnetic resonance (MR) imaging unit in fifty-one patients with bladder cancer including MIBC and NMIBC confirmed by histopathological findings. DWI data were postprocessed using mono-exponential and DKI models to calculate the apparent diffusion coefficient (ADC), apparent diffusional kurtosis (K), and kurtosis-corrected diffusion coefficient (D). Receiver-operating characteristic (ROC) analysis was performed to compare the diagnostic efficacy of all diffusion parameters.

RESULTS

All parameters differed significantly between MIBC and NIMBC including increased K, decreased D and ADC (all p < 0.001). Only the combination of D and K was significantly higher than ADC (p < 0.05), whilst D and K were not statistically different from ADC.

CONCLUSIONS

Both conventional DWI and DKI models are beneficial in differentiating between MIBC and NMIBC, whilst the combination of D and K can produce a more robust value than conventional ADC value in evaluating aggressiveness of bladder cancer.