PRESURGICAL STAGING OF BLADDER-CANCER USING GD-DTPA ENHANCED DYNAMIC MAGNETIC-RESONANCE-IMAGING - COMPARISON WITH PLAIN AND CONTRAST-ENHANCED MR-IMAGING

Purpose: Evaluation of dynamic Gd-DTPA enhanced MR imaging in the stag ing of bladder cancer. Methods: We studied 40 patients with histologic ally proven bladder cancer. All patients were examined with routine T- 1- and T-2-weighted MRI and late Gd-DTPA enhanced T-1-weighted MRI. Ad ditionally, a dynamic study was performed with 10 subsequent short FLA SH-2-D gradient echo sequences without delay immediately after bolus i njection of Gd-DTPA. Signal intensities of the tumour and of the surro unding tissue as well as image contrast parameters were quantified. Re sults: The dynamic study showed a higher accuracy in the evaluation of stage pT(a) to pT(2) cancer compared to spin echo MRI (63% and 46%, r espectively) and no difference regarding the sensitivity (87.5%). Howe ver, overstaging was a problem with both modalities. The contrast-to-n oise ratio of bladder tumour and muscle was equal or significant highe r with the dynamic study compared to spin echo MRI. A higher signal-to -contrast ratio of bladder tumour and bladder muscle was calculated fo r the dynamic study compared with the spin-echo MRI (p < 0.01; Mann-Wh itney U test). Conclusion. Dynamic Gd-DTPA enhanced MRI is recommended to be used additionally in tile preoperative staging of bladder neopl asms.