Localization of prostate cancer using 3T MRI: comparison of T2-weighted and dynamic contrast-enhanced imaging

OBJECTIVE: To compare dynamic contrast-enhanced imaging and T2-weighted imaging using a 3T MR unit for the localization of prostate cancer. METHODS: Twenty consecutive patients with biopsy-proven prostate cancer underwent both T2-weighted imaging and dynamic contrast-enhanced imaging. At T2-weighted imaging and dynamic contrast-enhanced imaging, the presence or absence of prostate cancer confined within the prostate without extracapsular or adjacent organ invasion was evaluated in the peripheral zones of base, mid-gland, and apex on each side. Final decisions on prostate cancer localization were made by consensus between two radiologists. Degrees of depiction of tumor borders were graded as poor, fair, or excellent. RESULTS: Prostate cancer was pathologically detected in 64 (53%) of 120 peripheral zone areas. The sensitivity, specificity, and accuracy for prostate cancer detection were 55%, 88% and 70% for T2-weighted imaging and 73%, 77%, and 75% for dynamic contrast-enhanced imaging, respectively. Three cancer areas were detected only by T2-weighted imaging, 15 only by dynamic contrast-enhanced imaging, and 34 by both T2-weighted imaging and dynamic contrast-enhanced imaging. A fair or excellent degree at depicting tumor border was achieved in 67% by T2-weighted imaging and in 90% by dynamic contrast-enhanced imaging (P<0.05). CONCLUSIONS: Dynamic contrast-enhanced imaging at 3T MRI is superior to T2-weighted imaging for the detection and depiction of prostate cancer and thus is likely to be more useful for preoperative staging.