MAGNETIC-RESONANCE-IMAGING IN THE STAGING OF BLADDER-CANCER

Magnetic resonance imaging (MRI) scans were performed on 55 bladder ca ncer patients on whom clinicopathological staging was available from t ransurethral resection and cystectomy specimens. The overall accuracy of MRI scanning in this group was 84%, although true concordance rates are debatable without open surgical correlation. In the subgroup of 2 5 patients who had accurate open surgical correlation (from cystectomy , laparotomy or post mortem) the concordance rate was 76% with MRI. Er rors occurred mainly in the T3 group of tumours, with 2 being overstag ed and 2 being understaged out of a total of 12 in the open surgical c orrelation group (66% accuracy). Difficulties were also encountered in staging tumours at the bladder base, with an error rate of 22% (2 of 9) for T4 tumours in this area. With regard to lymph node staging ther e was a 100% (5 of 5) specificity in defining pathologically involved nodes but there was a false negative rate of 15% (3 of 19). Although i t has many advantages over CT scanning, MRI produces a significant err or rate in terms of over- and under-staging invasive tumours. There ar e difficulties associated with detecting minimal involvement of adjace nt organs and lymph nodes as well as determining the exact depth of mu scle penetration. Improvements may come in the future with the use of contrast enhancement agents such as gadolinium as well as more advance d machines.