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

Abstract

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 T 1 , a multiecho measurement of T 2 , 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 (F b ), extraction fraction (E), mean transit time (T c ), and extravascular-extracellular volume (v e ) 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, F b , and v e had median CVs of Յ6%, Յ4 %, and Յ5%, respectively. Reproducibilities of the T 1 and T 2 measurements were excellent (wCV Յ 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 T 1 and T 2 were highly reproducible.

Dynamic Contrast-enhanced CT for Prostate Cancer: Relationship between Image Noise, Voxel Size, and Repeatability

“…the repeatability of DCE MR imaging in prostate cancer, our results in terms of wCV are similar for K trans , with a higher wSD for v e ( 30,32,33 ). Contrary to other studies ( 23,28,31 ), we found that the repeatability of K trans in terms of wCV is the same as v e .…”

Tracer kinetic analysis of dynamic contrast‐enhanced MRI and CT bladder cancer data: A preliminary comparison to assess the magnitude of water exchange effects

“…Estimates of all parameters apart from v e were unaffected, and so parameter estimates are shown for those datasets appropriate for a 2CXM (eight patients), with three of these lacking an estimate of v e . A potential solution to enable v e estimates in all patients is to increase the acquisition length to allow more time for contrast agent equilibration (47), but this must be set against ionizing radiation dose escalation for the CT studies.…”

Prostate T1 quantification using a magnetization‐prepared spiral technique

“…The poor agreement of VFA with T1prep and inversion recovery measurements within an in vitro phantom may expose a flip-angle dependence of the SPGR slice profile (private commun., Dr. Hai-Ling Margaret Cheng), but formal evaluation is outside of the scope of this article. The most relevant contemporary comparison may be the application by Kershaw et al (24) of a 3D-inversion recovery turbo field echo technique for prostate evaluation at 1.5 T, achieving 2 Â 2 Â 5 mm interpolated voxels within a 4-minute scan time, although representative images were not provided.…”