CONTRIBUTION OF MRI TO THE EVALUATION OF BLADDER-CARCINOMA SPREAD - A PROSPECTIVE-STUDY IN 42 CASES

Forty-two patients underwent magnetic resonance imaging to evaluate a carcinoma of the bladder. Results were compared with pathologic findings in cystoprostatectomy specimens (n = 31) or resection specimens (n = 11). A supra-conductor magnet (0.5 T) was used and T1 and T2-weighted sequences were obtained; section planes were perpendicular to each other and to the lesion. An intact low signal line from the bladder wall on T2-weighted sequences was found to be a reliable indicator of lack of spread to the deep muscle layer. Conversely, an abnormal bladder wall low signal line was associated with spread to the deep muscle layer in 60% of cases. Sensitivity of MRI for extension to perivesical fat was 85 %. MRI correctly evaluated involvement of neighboring organs in every case, but all these lesions were visible upon gross examination. MRI detected 66 % of involved lymph nodes.