Abstract 350: Detection of VCAM-1 Expression in Inflammatory Atherosclerosis Using Targeted Ultrasound-based Molecular Imaging
Background: Endothelial adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1) play an important role in atheroma development and are suitable target for molecular imaging.
Purpose: To detect VCAM-1 expression in association with inflammatory atherosclerosis by non-invasive ultrasound-based molecular imaging techniques.
Methods: Targeted microbubbles (MBv) and control microbubbles (MBc) were prepared by reacting the Targestar-B microbubbles with a biotinylated anti-mouse VCAM-1 antibody or an isotype IgG antibody. Western diet-fed apoE deficient and control mice were injected with 5×106 MBv or MBc. Inominate and right common carotid arteries were imaged with a high-frequency ultrasound transducer. Contrast enhanced imaging was performed with Contrast Pulse Sequencing. Tightly bound and freely circulating microbubbles in the region of interest (ROI) were differentiated by a destructive ultrasound pulse MI 1.0) for 1 sec. Highlighting intensity and post-destructive analysis were performed using the Siemens ACQ software.
Results: In apoE deficient mice, both MBv and MBc reached similar peak intensity immediately after injection (Fig. 1B⇓). At 15 min, there was more retention of MBv than MBc in the region of interest, with an increase in highlighting intensity of 2 dB. Post-destructive analysis demonstrated specific targeting by MBv. In control mice, the retention of MBv and MBc was similar (data not shown).
Conclusion: Ultrasound imaging with Contrast Pulse Sequencing can specific detect microbubbles with minimal interference from surrounding tissues. This permits detection of inflammation in association with atherosclerosis.
This research has received full or partial funding support from the American Heart Association, National Center.