[The diagnostic value of MR tomography following gadolinium-DTPA compared to computed tomography in bladder tumors]

In a prospective study, 58 patients with carcinomas of the bladder were examined by CT and MRI; in 48, gadolinium-DTPA was administered intravenously. MRI provided exact staging in 89%, compared with 80% with CT. There was 13% over-staging with CT and 11% with MRI. MRI, unlike CT did not result in any under-staging. In 36 patients a quotient could be calculated from the signal intensity of the tumour and surrounding soft tissues both before and after the intravenous contrast medium and the increased quotient after contrast administration could be estimated. There was a significant increase in the tumour/muscle quotient with a mean of 72 +/- 22% (minimum 43%, maximum 153%), corresponding to a marked increase of the signal from the tumour when compared with the pre-contrast images. This had the following advantages compared with CT: accurate differentiation between superficial and intramural spread. MRI was better than CT at demonstrating tumours in the roof of the bladder and at the trigone.