[Preoperative staging of bladder carcinomas with Gd-DTPA-supported dynamic magnetic resonance tomography. Comparison with plain and Gd-DTPA-supported spin-echo sequences]

Abstract

Purpose: Evaluation of dynamic Gd-DTPA enhanced MR imaging in the staging of bladder cancer.

Methods: We studied 40 patients with histologically proven bladder cancer. All patients were examined with routine T1- and T2-weighted MRI and late Gd-DTPA enhanced T1-weighted MRI. Additionally, a dynamic study was performed with 10 subsequent short FLASH-2-D gradient echo sequences without delay immediately after bolus injection of Gd-DTPA. Signal intensities of the tumour and of the surrounding tissue as well as image contrast parameters were quantified.

Results: The dynamic study showed a higher accuracy in the evaluation of stage pTa to pT2 cancer compared to spin echo MRI (63% and 46%, respectively) and no difference regarding the sensitivity (87.5%). However, overstaging was a problem with both modalities. The contrast-to-noise ratio of bladder tumour and muscle was equal or significant higher with the dynamic study compared to spin echo MRI. A higher signal-to-contrast ratio of bladder tumour and bladder muscle was calculated for the dynamic study compared with the spin-echo MRI (p < 0.01; Mann-Whitney U test).

Conclusion: Dynamic Gd-DTPA enhanced MRI is recommended to be used additionally in the preoperative staging of bladder neoplasms.