A compact solution for estimation of physiological parameters from ultrafast prostate dynamic contrast enhanced MRI.

In this study, we present a compact solution allowing estimation of physiological parameters K<sup>trans</sup> and v<sub>e</sub> from ultrafast DCE acquisitions, without fitting DCE-MRI data to the standard Tofts pharmacokinetic model. Since the standard Tofts model can be simplified to the Patlak model at early times when contrast efflux from the extravascular extracellular space back to plasma is negligible, K<sup>trans</sup> can be solved explicitly for a specific time. Further, v<sub>e</sub> can be estimated directly from the late steady-state signal using the derivative form of Tofts model. Ultrafast DCE-MRI data were acquired from 18 prostate cancer patients on a Philips Achieva 3T-TX scanner. Regions-of-interest (ROIs) for prostate cancer, normal tissue, gluteal muscle, and iliac artery were manually traced. The contrast media concentration as function of time was calculated over each ROI using gradient echo signal equation with pre-contrast tissue T1 values, and using the 'reference tissue' model with a linear approximation. There was strong correlation (r = 0.88 to 0.91, p < 0.0001) between K<sup>trans</sup> extracted from the Tofts model and K<sup>trans</sup> estimated from the compact solution f...
Source: Physics in Medicine and Biology - Category: Physics Authors: Tags: Phys Med Biol Source Type: research