Noninvasive imaging for staging of prostate cancer: magnetic resonance imaging, computed tomography, and ultrasound.

The diagnosis of prostate carcinoma by imaging is still fraught with problems, even with the advent of highly sophisticated techniques. Despite enthusiastic preliminary reports, no one imaging method reliably screens for this condition. The staging of prostate carcinoma is feasible, but the best imaging method remains a subject of debate. The transabdominal sonographic approach lacks the resolution required for detailed intraglandular anatomic delineation. The transrectal sonographic approach excels in guiding needle biopsy and in evaluating transcapsular and seminal vesicle extension of known tumors. Computed tomography lags behind other tomographic imaging modalities in its accuracy for local tumor staging, but it is excellent, although nonspecific, in the detection of lymph node enlargement. Magnetic resonance detects abnormalities in the prostate in a high percentage of cases but is nonspecific. However, it can stage prostate carcinoma and detect lymphadenopathy reliably.