Evaluation of normal prostate tissue, chronic prostatitis, and prostate cancer by quantitative perfusion analysis using a dynamic contrast-enhanced inversion-prepared dual-contrast gradient echo sequence

Abstract

Objective:: To quantify independent pharmacokinetic parameters for differentiation of prostate pathology. Material and methods:: Twenty-seven patients with biopsy-proven prostate cancer (PSA: 1.4-16.1 ng/mL) underwent magnetic resonance imaging with a new dynamic contrast-enhanced, inversion-prepared dual-contrast gradient echo sequence (T1/T2*-weighted, 1.65 seconds temporal resolution) using a combined endorectal/body phased-array coil at 1.5 Tesla. Perfusion, blood volume, mean transit time, delay, and dispersion were calculated using a sequential 3-compartment model. Twenty-three patients underwent prostatectomy. For histologic correlation a pathologist mapped areas of normal prostate tissue, chronic prostatitis, and prostate cancer (total of 63 areas) on histologic sections corresponding to the magnetic resonance imaging planes. Results:: Compared with normal prostate tissue, low-grade cancer (Gleason score ≤6) only showed higher perfusion (1.01 mL/cm/min vs. 0.26 mL/cm/min, P = 0.050), whereas high-grade cancer showed higher perfusion (1.21 mL/cm/min vs. 0.26 mL/cm/min, P ≤ 0.001), higher blood volume (1.44% vs. 0.95%, P = 0.005), shorter mean transit time (3.55 seconds vs. 4.40 seconds, P = 0.019), shorter delay (10.15 seconds vs. 13.36 seconds, P = 0.015), and smaller dispersion (8.56 seconds vs. 12.11 seconds, P = 0.020). High-grade cancer showed higher perfusion than chronic prostatitis (1.21 mL/cm/min vs. 0.90 mL/cm/min, P = 0.041). Chronic prostatitis showed higher perfusion (0.90 mL/cm/min vs. 0.26 mL/cm/min, P = 0.006), higher blood volume (1.53% vs. 0.95%, P = 0.046), shorter delay (11.42 seconds vs. 13.36 seconds, P = 0.015), and smaller dispersion (10.49 seconds vs. 12.11 seconds, P = 0.020) than normal prostate tissue. There were no statistically significant differences between low-grade and high-grade cancer or between low-grade cancer and chronic prostatitis. Conclusion:: The pharmacokinetic parameters investigated, especially perfusion, allow statistically significant in situ differentiation of normal prostate tissue from cancer and chronic prostatitis and of high-grade cancer from chronic prostatitis. Copyright © 2008 by Lippincott Williams & Wilkins.