Mitsuru Takeuchi MD, Presenter: Nothing to Disclose

Shinsuke Okada, Abstract Co-Author: Nothing to Disclose

Shigeru Sasaki MD, Abstract Co-Author: Nothing to Disclose

Masato Ito MD, PhD, Abstract Co-Author: Nothing to Disclose

Masaki Hara MD, PhD, Abstract Co-Author: Nothing to Disclose

Yuta Shibamoto MD, PhD, Abstract Co-Author: Nothing to Disclose

Hidekazu Oshima, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

To investigate the utility of diffusion-weighted image (DWI) in bladder cancer patients.

MRI was performed in 16 patients (22 tumors) on a 1.5-T scanner (Intera, Philips) with a cardiac coil between July 2006 and March 2007. T2-weighted fast spin-echo images (T2WI) and high-b (=1000) value DWI with chemical shift selective pulse were obtained at sections perpendicular to the tumor base in all 22 tumors. ADC map was evaluated in 17 tumors. Contrast-enhanced T1-weighted fast spin-echo images with fat suppression (CET1WI) were acquired for 19 tumors during a phase at which submucosa enhanced strongly. On DWI using an inverted gray-white scale and ADC map, the signal intensity of urine and submucosa, cancer, and bladder wall became high, low, and intermediate, respectively. We defined diagnostic criteria for both DWI and ADC map as follows; Ta, Tis, and T1: hyper-intense flat tumor and hypo-intense submucosal stalk, T2: no hypo-intense stalk or disrupted intermediate signal layer of smooth muscle, T3: hypo-intense area in perivesical fat, T4: extension to adjacent organs. Conventional staging criteria were used for interpreting T2WI and CET1WI. ADC values were calculated in 16 of 22 tumors and correlated with histological grade.

Detectability of tumors was 71% on T2WI and 77% on DWI, ADC map and CET1WI. No pTis tumors were depicted on DWI, ADC map, and CET1WI. Sensitivity and specificity for diagnosing pT2 and more advanced T stages were respectively 71% and 74% for T2WI, 71% and 100% for DWI, 80% and 100% for ADC map and 80% and 63% for CET1WI. On a stage-by-stage basis excluding pTis tumors, overall accuracy for diagnosing T stage was 71% for T2WI, 93% for DWI and ADC map and 67% for CET1WI. Correlation coefficient between ADC value and histological grade was -0.49.

Tumor detectablity on DWI and ADC map was higher than that of T2WI and equal to that of CET1WI. Although DWI and ADC map might be useful in differentiating pT1 from other stages, there was no correlation between ADC value and histological grade.

DWI and ADC map can correctly differentiate T1 from other stages and might be useful for T stage in bladder cancer patients.

Takeuchi, M, Okada, S, Sasaki, S, Ito, M, Hara, M, Shibamoto, Y, Oshima, H, et al, , et al, , High-b-value Diffusion-weighted MRI of Urinary Bladder Cancer: Evaluation of Detectability, Staging Accuracy, and Histological Grade.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5002090.html