Ultrasmall Superparamagnetic Iron Oxide-enhanced Magnetic Resonance Imaging of Abdominal Aortic Aneurysms–A Feasibility Study

ObjectivesAbdominal aortic aneurysms (AAAs), being predominantly atherosclerotic in nature, have underlying inflammatory activity. As it is well established that ultrasmall superparamagnetic iron oxide (USPIO) particles accumulate in the macrophages within atheromatous lesions, USPIO-enhanced magnetic resonance (MR) imaging can be potentially effective in the quantification of the associated inflammatory processes.MethodsA total of 14 patients underwent USPIO-enhanced MR imaging using a 1.5T-MR system. Quantitative T2* and T2 relaxation time data were acquired before and 36 h after UPSIO infusion at identical AAA locations. The pre- and post-USPIO-infusion relaxation times (T2∗ and T2) were quantified and the correlation between pre- and post-USPIO infusion T2* and T2 values was investigated.ResultsThere was a significant difference between pre- and post-infusion T2* and T2 values (both respective p-values = 0.005). A significant correlation between T2* and T2 values post-USPIO infusion was observed (r = 0.90, p < 0.001), which indicates USPIO uptake by the aortic wall.ConclusionsAortic wall inflammation using USPIO-enhanced MR imaging is feasible. Use of quantitative T2 and T2* pulse sequences provides a quantitative method for assessing USPIO uptake by the aortic wall.