Dynamic MRI of bladder cancer: evaluation of staging accuracy.
OBJECTIVE
The purpose of this study was to evaluate the accuracy of gadoliniumenhanced MRI in staging bladder cancer in a series of patients with surgically proven bladder cancer.


METHODS
Seventy-one patients with biopsy-proven bladder cancer underwent MRI on a 1.5-T scanner with a phased-array pelvic coil. Conventional T1-weighted spin-echo, T2-weighted spin-echo, and unenhanced and enhanced (0.1 mmol/kg gadolinium) fast spoiled gradient-echo images with fat suppression were obtained. Two blinded reviewers evaluated the MR images and assigned a stage that was compared with the pathologic stage (n = 67) or with clinical follow-up for at least 2 years after MRI (n = 4).


RESULTS
Agreement among the reviewers was good in assigning a radiologic stage for bladder cancer (kappa = 0.80). On a stage-by-stage basis, MRI accuracy was 62%, and overstaging was the most common error (32%). Staging accuracy improved to 85% and 82% in differentiating superficial from invasive tumors and organ-confined from non-organ-confined tumors, respectively. The time interval between MRI and transurethral resection (</= 60 days and >/=61 days) was not a statistically significant factor in differentiating superficial from invasive and organ-confined from non-organ-confined tumors (p > 0.05). MRI accuracy in staging transitional cell carcinoma was not significantly different from that obtained in staging non-transitional cell carcinoma (p > 0.05).


CONCLUSIONS
MRI shows good reproducibility between reviewers for staging bladder cancer. Although overall staging accuracy was only moderate, the accuracy for differentiating superficial versus invasive disease and organ-confined versus non-organ-confined disease was high.
Tekes
Aylin
A
Russell H. Morgan Department of Radiology, Johns Hopkins School of Medicine, 601 N Caroline St., Ste. 3235A, Baltimore, MD 21287, USA.
Kamel
Ihab
I
Imam
Khursheed
K
Szarf
Gilberto
G
Schoenberg
Mark
M
Nasir
Khurram
K
Thompson
Richard
R
Bluemke
David
D
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002295:Carcinoma, Transitional Cell / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D012680:Sensitivity and Specificity; D001749:Urinary Bladder Neoplasms / Q000473:pathology*
D003287:Contrast Media; D019786:Gadolinium DTPA