Quantification of abdominal aortic aneurysm wall enhancement with dynamic contrast-enhanced MRI : feasibility, reproducibility and initial experience

Keywords: dynamic contrast-enhanced MRI; abdominal aortic aneurysm; microvascularization; vessel wall imaging Purpose : To investigate the feasibility and reproducibility of dynamic contrast-enhanced MRI (DCE-MRI) to quantify abdominal aortic aneurysm (AAA) vessel wall enhancement dynamics which may reflect the amount of wall microvasculature. AAA vessel wall microvasculature has been linked with aneurysm progression and rupture. Materials and Methods : Thirty patients with AAA underwent DCE-MRI at 1.5 Tesla. Enhancement dynamics of the aneurysm wall were quantified in regions-of-interest (ROIs) in the vessel wall by calculating the transfer constant (Ktrans) using pharmacokinetic modeling and the area-under-gadolinium-curve (AUC). To assess reproducibility, 10 patients were imaged twice on different occasions. ROIs were drawn by two independent observers. The intraclass correlation coefficients (ICC) and coefficients of variation (CV) were determined to investigate intra-, interobserver, and interscan variability. Results : Twenty-eight analyzable MR examinations were included for pharmacokinetic analysis after excluding two examinations due to severe motion artifacts. Intra-, interobserver, and interscan variability for Ktrans were small (all ICC > 0.90, CV <14%) as well as for AUC measurements (all ICC > 0.88, CV <23%). Conclusion: Quantitative analysis of AAA vessel wall enhancement dynamics with DCE-MRI is feasible and reproducible. J. Magn. Reson. Imaging 2014;39:1449–1456. © 2013 Wiley Periodicals, Inc.