Patients with a history of elevated prostate-specific antigen levels and negative transrectal US-guided quadrant or sextant biopsy results: value of MR imaging.
OBJECTIVE
To determine the role of magnetic resonance (MR) imaging performed with a combined endorectal body phased-array coil for patients with elevated prostate-specific antigen (PSA) levels or suspicious free-to-total PSA ratios in whom prior transrectal ultrasonographically (US) guided biopsy findings were negative for prostate cancer.


METHODS
Forty-four patients with PSA levels greater than 4 ng/mL or free-to-total PSA ratios lower than 15% but negative biopsy findings were examined with T1- and T2-weighted MR imaging at 1.5 T with a combined endorectal body phased-array coil. All patients underwent digital rectal examination (DRE) and transrectal US. Thirty-eight patients underwent repeat biopsy after MR imaging. The accuracy of MR imaging for detection of prostate cancer was assessed prospectively. Retrospectively, MR imaging findings were correlated with individual biopsy site findings. MR imaging and biopsy results were correlated by using a cross table to calculate sensitivity, specificity, and positive predictive value (PPV). Retrospective analysis results were evaluated with receiver operating characteristic analysis. A P value of less than.05 indicated significance (chi(2) test according to Pearson).


RESULTS
At prospective analysis, MR imaging had a sensitivity of 83% and a PPV of 50% for detection of prostate cancer; these values were 33% and 67%, respectively, for DRE and 33% and 57%, respectively, for transrectal US. At retrospective site-by-site analysis, MR imaging results did not correlate significantly with individual biopsy site findings (P =.126); sensitivity was 65% and PPV was 12%.


CONCLUSIONS
In this patient population, MR imaging has higher sensitivity for detection of prostate cancer than DRE or transrectal US.
Department of Radiology, Charité, Humboldt-Universität, Schumannstrasse 20/21, 10117 Berlin, Germany. dirk.beyersdorff@charite.de
Dirk
D
Beyersdorff
Matthias
M
Taupitz
Bjoern
B
Winkelmann
Thomas
T
Fischer
Severin
S
Lenk
Stefan A
SA
Loening
Bernd
B
Hamm
D000368:Aged; D001706:Biopsy / Q000379:methods*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010173:Palpation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011467:Prostate / Q000000981:diagnostic imaging / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000032:analysis*; D011471:Prostatic Neoplasms / Q000175:diagnosis*; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014463:Ultrasonography
D017430:Prostate-Specific Antigen