%0 Generic
%A Uhrig, Tanja
%C Heidelberg
%D 2020
%F heidok:28512
%R 10.11588/heidok.00028512
%T Quantitative Dynamic Contrast-Enhanced Perfusion MRI - A Phantom and in Vivo Study
%U https://archiv.ub.uni-heidelberg.de/volltextserver/28512/
%X Quantitative Dynamic Contrast-Enhanced Perfusion MRI - A Phantom and in Vivo Study  The quantification of tissue perfusion with magnetic resonance imaging (MRI) is of great medical value for tumor diagnosis, treatment planning and therapy control. The aim  of this work was to evaluate the feasibility as well as to find limitations and improvements of perfusion quantification using dynamic contrast-enhanced (DCE) MRI in combination with pharmacokinetic modeling. In the first part, a multimodal perfusion phantom mimicking human  physiology at capillary level and simulating intra- and extravascular space was developed.  This enables the application of a dual compartment model leading to perfusion parameters of which among others the Plasma Flow PF shows reproducible values both within a series of measurements (PF = (91 ± 7) ml/100 ml/min) and in the repetition after one week (PF = (91 ± 26) ml/100 ml/min). A reliable comparison not only between MRI and DCE computer tomography (CT) (PF = (94 ± 53) ml/100 ml/min), but also to the alternative MRI perfusion technique Arterial Spin Labeling (ASL) (PF = (99 ± 36) ml/100 ml/min) is applicable. Fast temporal resolution through a high sampling rate, indispensable for exact modeling, was  achieved by the implementation of parallel imaging and led to a significant reduction of the intra measurement deviation by 30%. In the second part, an in vivo perfusion study of rectal carcinomas showed that the bilateral selection of the arterial input function and the use of dual  compartment models have a significant influence on the quantification of perfusion parameters with deviations of the PF of up to 30 ml/100 ml/min. The importance of tissue ROI selection in heterogeneous tumors has been shown, as the parameters within a tumor differ by up to 36%. The combination of the findings of the phantom and the patient study reveals new and promising strategies for quantifying DCE-MRI in the future.