David Planer MD, Abstract Co-Author: Nothing to Disclose

Galit Kafri PhD, Abstract Co-Author: Nothing to Disclose

Liran Goshen PhD, Abstract Co-Author: Employee, Koninklijke Philips Electronics NV

Raz Carmi PhD, Abstract Co-Author: Employee, Koninklijke Philips Electronics NV, Haifa, Israel

Rachel Surani, Abstract Co-Author: Nothing to Disclose

Jacob Sosna MD, Presenter: Consultant, ActiViews Ltd Advisory Board, CMT Medical Technologies Ltd Research grant, Koninklijke Philips Electronics NV

Macrophages accumulate in vulnerable atherosclerotic plaques. Our purpose was to assess if dual energy MDCT improves the visualization of macrophage specific iodine based nanoparticulate contrast (NPC) attached to rabbit's atherosclerotic plaques.

Advanced atherosclerotic plaques were induced in 12 NZW rabbits using high cholesterol diet and repeated aortic endothelial denudation. Four non-atherosclerotic rabbits served as negative controls. Rabbits were scanned with a single source dual energy MDCT (Orion N, Philips Healthcare, Cleveland, OH) after 6 months. N1177 NPC (NanoScan Imaging, Landsdale, PA) was injected to the marginal ear vein. Dual energy imaging was performed precontrast, 10 minutes after injection and 2 hours after the injection. Aortic lumen narrowing and late vessel wall NPC accumulation were analyzed. Spectral analysis was performed on late scans. The rabbits were sacrificed after the scan and the aorta was microscopically evaluated for atherosclerosis and macrophage content.

High cholesterol diet and endothelial denudation resulted in complex atherosclerotic plaques. CT demonstrated irregular vessel wall with mild (up to 25%) narrowing of the lumen in atherosclerotic rabbits, with normal aorta in the control rabbits. Late scanning of the study group demonstrated localized NPC accumulation in atherosclerotic lesions with improved visualization using spectral analysis in comparison to regular CT images. No delayed enhancement of the vessel wall was demonstrated in control animals. Microscopic evaluation of atherosclerotic plaques demonstrated correlation between plaque's, macrophages content and aortic NPC accumulation.

NPC accumulated in atherosclerotic plaques that had lesions rich with macrophages. Spectral analysis enhanced the visualization of the macrophages attached to iodine based contrast agent.

NPC is useful in identifying vulnerable plaques abundant with macrophages. Dual energy scan enables improved visualization of plaque composition and may be used in the future for identifying patien

Planer, D, Kafri, G, Goshen, L, Carmi, R, Surani, R, Sosna, J, The Vulnerable Atherosclerotic Plaque: Enhanced Characterization with Macrophage Specific Iodinated Nanoparticles and Dual-energy MDCT.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8007546.html