Accuracy of CT staging of bladder neoplasms using the gas-filled method: report of 21 patients with surgical confirmation.

CT staging of bladder neoplasms is a highly accurate procedure with a proven accuracy rate of 81% and a potential accuracy rate probably above 90%. At this institution, CT staging has become a routine procedure for all patients with bladder neoplasms prior to surgery or radiotherapy as well as to follow the progress of therapy. Staging of bladder carcinoma is performed by cystoscopy with biopsy, intravenous urography, and CT of the gas-filled bladder. Of 21 patients with surgical confirmation, 17 were correctly staged solely from the CT image. Overstaging in the four errors resulted from confusion produced by normal contiguous extravesical structures and by tangential viewing of the normal bladder wall. Negative contrast allowed precise demonstration of the morphology of the intravesical portion of the tumor.