Benign prostatic hyperplasia: evaluation of T1, T2, and microvascular characteristics with T1-weighted dynamic contrast-enhanced MRI

PURPOSE: To evaluate microvascular and relaxation parameters of prostate and nearby muscle in patients with benign prostatic hyperplasia (BPH), and to examine measurement reproducibility.

MATERIALS AND METHODS: In this prospective study, 13 patients with BPH were imaged twice prior to surgery. The imaging protocol included a three-dimensional (3D) inversion-recovery turbo field-echo measurement of T1, a multiecho measurement of T2, and a high temporal resolution (1.5 seconds per volume) dynamic contrast-enhanced (DCE) acquisition. The DCE data were analyzed using a distributed parameter tracer kinetics model to provide estimates of perfusion (Fb), extraction fraction (E), mean transit time (Tc), and extravascular-extracellular volume (ve) in both the central gland (CG) and the peripheral zone (PZ) of the prostate, and in nearby muscle. Precision of these estimates was calculated using a bootstrap technique and the reproducibility was evaluated using the within-patient coefficient of variation (wCV).

RESULTS: The microvascular parameters were estimated in the prostate with high precision; in particular, E, Fb, and ve had median CVs of <or=6%, <or=4%, and <or=5%, respectively. Reproducibilities of the T1 and T2 measurements were excellent (wCV<or=4%), and reproducibility of the other parameters reflected values seen in previous studies.

CONCLUSION: Microvascular and relaxation properties of BPH can be measured precisely with reproducibilities for a distributed parameter tracer kinetics model that are comparable to those for a simpler model. Measurements of T1 and T2 were highly reproducible.