Detection of extracapsular extension of prostate carcinoma with endorectal and phased-array coil MR imaging: multivariate feature analysis.
OBJECTIVE
To determine which magnetic resonance (MR) imaging features are most predictive of extracapsular extension of prostate carcinoma.


METHODS
In 77 patients who had stage pT2 or pT3 prostate carcinoma, MR images were retrospectively reviewed by three readers with varying experience in interpretation of endorectal coil images of the prostate gland. MR imaging features assessed were broad tumor contact, smooth capsular bulge, irregular bulge, obliteration of the rectoprostatic angle, and asymmetry of the neurovascular bundle. Multivariate logistic regression analysis was performed to determine the relative value of each MR imaging feature.


RESULTS
At multivariate analysis, obliteration of the rectoprostatic angle and asymmetry of the neurovascular bundle were most predictive of extracapsular extension, with a specificity of up to 95% and sensitivity of 38%. Poor-quality images reduced accuracy for all readers. The most experienced reader demonstrated overall accuracy of 77% in determination of extracapsular extension.


CONCLUSIONS
Obliteration of the rectoprostatic angle and asymmetry of the neurovascular bundle were most indicative of extracapsular extension. Reader experience plays an important role in the ability to interpret prostate MR images and is an important contributor to interobserver variability.
Yu
K K
KK
Department of Radiology, University of California, San Francisco 94143, USA.
Hricak
H
H
Alagappan
R
R
Chernoff
D M
DM
Bacchetti
P
P
Zaloudek
C J
CJ
D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D016015:Logistic Models; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D015588:Observer Variation; D011237:Predictive Value of Tests; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity