Use of pelvic surface coil MR imaging for assessment of clinically localized prostate cancer with histopathological correlation

We evaluated the ability of magnetic resonance imaging (MRI) operating at 1 .0 Tesla with a Helmholz pelvic surface coil to predict the pathological st age of prostate carcinoma, Radiological diagnosis was based on fast spin-ec ho axial T2-weighted images with and without frequency selective fat-suppre ssion and fast spin-echo coronal T2-weighted images. Thirty-one consecutive patients (mean age 61 years, range 49 to 71 years) underwent pelvic MRI be fore radical prostatectomy. Correlation with whole-mount step-sections of t he surgical specimens showed that the tumours were correctly localized in a ll but one prostate gland in,which the tumour could not be seen on pelvic M RI. The transverse diameter of the visible tumour at pelvic MRI appeared to represent an approximate estimate of the true tumour dimension. Based on h istopathologic whole-mount step-sections of the surgical specimens, 22 of 3 1 patients (71%) had tumours extending beyond the confines of the prostatic capsule. The specificity for MRI to predict capsular penetration and semin al,vesicle invasion was relatively high (0.80 and 0.86, respectively). The sensitivity was acceptable for capsular penetration (0.62) but poor for sem inal vesicle invasion (0.30).