Targeted contrast agent helps to monitor advanced plaque during progression: a magnetic resonance imaging study in rabbits.

Abstract

OBJECTIVE:

Gadofluorine M has been reported to enhance early atherosclerotic plaque signals in magnetic resonance imaging (MRI). The aim of this study was to examine the use of Gadofluorine M to monitor the progression of advanced plaques in a rabbit model.

METHODS:

Focal advanced atherosclerosis was induced in the right femoral arteries of 6 New Zealand white rabbits using a combination of cholesterol-enriched diet, and sequential air-desiccation, and balloon-overstretch injury. MRI with conventional 3 contrasts (T1, T2, and proton density [PD]) was performed to monitor the progression of the atherosclerotic plaques with 2 MRI scans separated by 4 to 8 weeks. Gadofluorine M was given intravenously to the rabbits 24 hours before the first MRI scans, and before (n = 3) or during (n = 3) the second MRI scan. The left femoral arteries were used as a control. Histopathologic images localized individual plaque components.

RESULTS:

The advanced plaque displayed multilayered neointima that included foam cells, smooth muscle cells, and extracellular matrix. The separate image contrasts offered similar T1-weighted enhancement patterns, but the combination of all 3 contrasts helped to delineate plaque and lumen boundaries. Gadofluorine M strongly enhanced neointima areas with an image contrast (contrast-to-noise ratio [CNR]) of approximately 15, versus 2 in the control femoral arterial wall. With improved images, significant changes in neointima and total plaque volumes over the 4 to 8 weeks between scans could be identified. Gadofluorine M remained within the plaques with significant image enhancements (contrast-to-noise ratio = 5.8) for 2 months after a single injection.

CONCLUSION:

This preliminary study in rabbits indicated that Gadofluorine M provides specific enhancements of components associated with advanced atherosclerotic plaques and may help to monitor the progression of the plaque in a rabbit model of atherogenesis.

• Authors: Jie Zheng, Elizabeth Ochoa, Bernd Misselwitz, Deshan Yang, Issam El Naqa, Pamela K Woodard, Dana Abendschein
• Journal: Investigative radiology (Invest Radiol) Vol. 43 Issue 1 Pg. 49-55 (Jan 2008) ISSN: 0020-9996 [Print] United States
• PMID: 18097277 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Contrast Media
• Fluorocarbons
• Organometallic Compounds
• gadofluorine M

Topics

• Algorithms
• Animals
• Atherosclerosis (diagnosis)
• Contrast Media
• Disease Models, Animal
• Disease Progression
• Drug Delivery Systems (methods)
• Feasibility Studies
• Fluorocarbons
• Image Enhancement (methods)
• Image Interpretation, Computer-Assisted (methods)
• Magnetic Resonance Imaging (methods)
• Organometallic Compounds (administration & dosage)
• Rabbits
• Reproducibility of Results
• Sensitivity and Specificity