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Objective: Our purpose was to evaluate MR imaging-based virtual endoscopy in patients with urinary bladder cancer compared with conventional cystoscopy as the gold standard., Subjects and Methods: Twenty-five patients with urinary bladder cancer diagnosed on conventional cystoscopy underwent MR imaging of the pelvis. Patients were examined without external bladder filling or administration of IV contrast medium. No medications were administered. The data obtained by MR imaging were reconstructed for virtual endoscopy on a workstation. The locations and sizes of tumors were individually determined and compared with results of conventional cystoscopy., Results: Twenty-four patients were evaluated; one patient's examination was excluded from analysis because of metallic artifacts. Seventeen patients were diagnosed with a single bladder tumor. Five patients had two tumors each, and two patients had three tumors. Tumor diameter ranged from 0.4 to 6.4 cm. Thirty (90.9%) of 33 tumors detected on cystoscopy were visualized with virtual endoscopy. The detection rate for 23 tumors of 1 cm or greater was 100%. Difficult conditions for conventional cystoscopy, including hematuria, anterior wall involvement, and urethral strictures, had no deleterious impact on virtual cystoscopy. Difficulties in detection on virtual endoscopy were associated with flat bladder tumors with minimal surface elevation., Conclusion: The results of this study suggest a high reliability in the diagnosis of urinary bladder cancer by MR imaging-based virtual cystoscopy-a noninvasive method, independent of medication or contrast enhancement, that may be of value for screening, primary diagnosis, and surveillance. Virtual MR cystoscopy may be indicated when conventional cystoscopy cannot be performed or is ineffective.

The purpose of the study was to assess the diagnostic performance of MR cystography with virtual cystoscopic and multiplanar reconstructions for detection of malignant bladder tumors. Thirty-two patients with 43 bladder tumors previously confirmed by cystoscopy (mean size 2.5 cm; 0.4-9.1 cm;) were examined at 1.5 T with a three-dimensional T2-weighted turbo spin echo sequence (TR=2911 ms, TE=500 ms, echo train length 256). Virtual cystoscopic reconstructions (VC) and multiplanar reconstructions (MPR) were obtained and analyzed separately by three radiologists without knowledge of the tumor location. Intraoperative or cystoscopic findings served as standard of reference. Sensitivities and specificities were calculated using a receiver-operating characteristic analysis with five levels of confidence. Area-under-curve values were similar for MPRs (0.952), VC (0.932) and the combination of both methods (0.954). Optimal sensitivity was 92.3% for MPR and 90.7% for VC, respectively, with a specificity of 91.1% for MPR and 90.4% for VC. The combination of MPR and VC resulted in a sensitivity of 90.7% and specificity of 94.0%. MR cystography is a promising, completely non-invasive technique for the detection of bladder lesions with a high diagnostic performance. [ABSTRACT FROM AUTHOR]