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.