- 作者：Grigorios Korosoglou ; Robert G. Weiss ; Dorota A. Kedziorek ; Piotr Walczak ; Wesley D. Gilson ; Michael Schä ; r ; David E. Sosnovik ; Dara L. Kraitchman ; Raymond C. Boston ; Jeff W.M. Bulte ; Ralph Weissleder ; Matthias Stuber
- 关键词：atherosclerosis ▪ ; vulnerable plaque ▪ ; superparamagnetic nanoparticles ▪ ; molecular imaging ▪ ; inversion recovery with ON-resonant water suppression (IRON) ▪ ; positive contrast ▪ ; magnetic resonance imaging
- 刊名：Journal of the American College of Cardiology
- 出版年：2008
- 出版时间：5 August 2008
- 年：2008
- 卷：52
- 期：6
- 页码：483-491
- 全文大小：1523 K
Objectives
This study was designed to identify macrophage-rich atherosclerotic plaque noninvasively by imaging the tissue uptake of long-circulating superparamagnetic nanoparticles with a positive contrast off-resonance imaging sequence (inversion recovery with ON-resonant water suppression [IRON]).Background
The sudden rupture of macrophage-rich atherosclerotic plaques can trigger the formation of an occlusive thrombus in coronary vessels, resulting in acute myocardial infarction. Therefore, a noninvasive technique that can identify macrophage-rich plaques and thereby assist with risk stratification of patients with atherosclerosis would be of great potential clinical utility.
Methods
Experiments were conducted on a clinical 3-T magnetic resonance imaging (MRI) scanner in 7 heritable hyperlipidemic and 4 control rabbits. Monocrystalline iron-oxide nanoparticles (MION)-47 were administrated intravenously (2 doses of 250 μmol Fe/kg), and animals underwent serial IRON-MRI before injection of the nanoparticles and serially after 1, 3, and 6 days.
Results
After administration of MION-47, a striking signal enhancement was found in areas of plaque only in hyperlipidemic rabbits. The magnitude of enhancement on magnetic resonance images had a high correlation with the number of macrophages determined by histology (p < 0.001) and allowed for the detection of macrophage-rich plaque with high accuracy (area under the curve: 0.92, SE: 0.04, 95 % confidence interval: 0.84 to 0.96, p < 0.001). No significant signal enhancement was measured in remote areas without plaque by histology and in control rabbits without atherosclerosis.
Conclusions
Using IRON-MRI in conjunction with superparamagnetic nanoparticles is a promising approach for the noninvasive evaluation of macrophage-rich, vulnerable plaques.