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.

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 <or=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 <or= 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.