Multiple directional DWI combined with T2WI in predicting muscle layer and Ki‐67 correlation in bladder cancer in 3.0‐T MRI

OBJECTIVE: To investigate the value of 3.0T MRI multi‐directional diffusion‐weighted imaging (DWI) combined with T2WI morphological features and lesion distribution in preoperative prediction of muscle layer invasion of bladder cancer (BC) and the correlation with postoperative Ki‐67. MATERIALS AND METHODS: This retrospective study enrolled patients with BC between 2019 and 2021. Patients with muscular invasive bladder cancer (MIBC) or non‐muscular invasive BC (NMIBC) were also analyzed by preoperative 3.0T MRI aFostic efficacy. RESULTS: A total of 186 patients were enrolled. About 27 patients with MIBC (35 lesions in total) and 62 with NMIBC (99 lesions in total). We found the tumor with a larger size, a wide base, and a smaller apparent dispersion coefficient (ADC) value and normalized ADC(nADC) value, without a stalk, presenting a greater risk of muscle invasion. ADC value, nADC value, maximum diameter, and stalk were independently associated with muscle invasion. Lesions located at the bladder fundus or involvement of multiple sites were independently associated with muscle invasion compared to the bladder body. In combination with morphological features, the AUCs of ADC and nADC showed accuracies of 0.925 and 0.947–0.951, respectively. TADC and nTADC showed the best diagnostic efficacy in multiple respects. KI‐67 LI was negatively correlated with ADC and nADC values. CONCLUSIONS: This is the first report in which we found Multi‐directional DWI combined with T2WI in 3.0T MRI can be used to predict the muscle layer invasion of bladder cancer. ADC values reflect the muscular invasion of bladder cancer and show a moderate negative correlation with Ki‐67. It is especially suitable for bladder cancer patients with renal insufficiency or tumor recurrence.