Abstract 2425: MR Imaging of Atherosclerotic Lesions in Rabbit Aortas Using Gadofosveset
Introduction: MS-325 (Vasovist®, Schering AG, Germany) is an albumin-binding contrast agent. We hypothesized that MS-325 can be used as a contrast agent to detect atherosclerotic lesions in rabbit abdominal aortas. We compared the performance of MS-325 for contrast-enhanced plaque imaging with Gd-DTPA (Magnevist®, Schering AG, Germany).
Materials and methods: In 7 out of 14 male NZW rabbits, atherosclerotic plaque development was induced by balloon denudation. The remaining 7 rabbits were sham-operated and received regular rabbit chow. The diseased groups and controls were then subdivided into groups of 3–4 rabbits each: an MS-325 and a Gd-DTPA group. Subsequently, pre- and post-contrast MR imaging with a 3D, DIR TSE sequence was performed on a whole-body 1.5 Tesla MRI system using a synergy cardiac coil. Post-contrast imaging was performed at 5 times the elimination half-life of the contrast agents. Signal intensities (SI) of vessel wall and muscle were corrected for receiver gain and scaling. Signal enhancement (SE) was defined as the ratio between pre/post contrast vessel wall SI and pre-contrast muscle SI.
Results: All animals tolerated the experiments well. Mean SE for the MS-325 group was 2.2±0.7 for the atherosclerotic rabbits and 1.4±0.3 for controls (p=0.02). No significant SE differences between atherosclerotic and control rabbits were seen in the Gd-DTPA group (both 3.1±0.8, Figure 1⇓).
Conclusion: Post-MS-325 signal enhancement of atherosclerotic vessel wall is significantly larger than that of normal vessel wall. In contrast, Gd-DTPA enhanced MRI does not seem to be able to distinguish between atherosclerotic and normal arterial vessel walls of NZW rabbits.