DYNAMIC GADOLINIUM-ENHANCED MAGNETIC-RESONANCE-IMAGING IN STAGING OF SUPERFICIAL BLADDER-CANCER

Purpose: We evaluated the usefulness of dynamic enhanced magnetic reso nance imaging (MRI) in the staging of superficial tumors following a b olus administration of gadopentetate dimeglumine. Materials and Method s: In 48 patients with proved bladder tumors the results of preoperati ve plain spin echo T1 (repetition time/echo time 500/20 msec.) and T2 (repetition time/echo time 2,000/40 to 100 msec.)-weighted MRI, dynami c gadolinium-enhanced MRI (repetition time/echo time 200/15 msec.) and late gadolinium-enhanced MRI (repetition time/echo time 500/20 msec.) were compared and correlated with the histopathological findings. Res ults: Unenhanced spin echo T1 and T2-weighted MRI sequences were able to stage correctly 14 (56%) and 17 (68%) of 25 superficial bladder can cers, respectively. Muscular infiltration (stages pT2 and pT3a) was co rrectly depicted in 3 (27%) and 6 (54%) of 11 cases respectively, with over staging being the most frequent error. On the basis of the dynam ic gadolinium-enhanced T1-weighted MRI appearance, superficial involve ment-of the bladder wall was correctly assessed in 21 of 25 cases (84% ) and muscular infiltration (stages pT2 to pT3a) in 7 of 11 (63%). Del ayed enhanced T1-weighted sequences showed a low accuracy rate in stag ing superficial tumors (44%). The overall accuracy of T1 and T2-weight ed, dynamic T1-weighted and delayed T1-weighted MRI in staging bladder cancer was 58, 71, 81 and 56%, respectively. Conclusions: The use of gadolinium improved the accuracy of dynamic enhanced MRI in staging su perficial Madder cancer. On the contrary, delayed enhanced MRI was not useful for staging superficial bladder cancer. The degree of bladder distension was a determinant factor in staging superficial tumors.