IN VIVO QUANTIFICATION OF ATHEROSCLEROTIC
PLAQUE COMPONENTS WITH MRI IN A RABBIT MODEL OF ATHEROSCLEROSIS. AG Zaman, SG Worthley*, G Helft, V Fuster, ZA
Fayad, JT Fallon, JJ Badimon, Cardiovascular Institute, Mount Sinai School
of Medicine, New York, NY, 10029-6574, and the Cardiovascular Centre, Monash
Medical Centre, Clayton, VIC, 3168. Noninvasive high resolution MR imaging may be
used to serially study the effects of therapeutic interventions on
atherosclerotic plaque stabilization in
vivo. This stabilization results from changes in lesion composition. We
report the feasibility of MRI to quantify lipidic and fibrotic components of
lesions in a rabbit model. Thoracic and abdominal aortic atherosclerosis
was induced in New Zealand white rabbits (n=15) by a combination of atherogenic
diet and balloon injury. MRI of the aorta was performed in a clinical 1.5T
system. T2W and PDW images were obtained with fast spin echo sequences and an
in-plane resolution of 0.35mm. After euthanasia, histopathology sections were
matched with the MR images. A significant correlation between MRI and
histology (Oil red O staining) for analysis of lipidic (low signal on T2W,
r=0.81) and fibrous (high signal on T2W, r=0.86) areas was observed. Mean wall
thickness correlated significantly between MRI and histopathology. Noninvasive high resolution MRI allows
qualitative and quantitative analysis of aortic atherosclerotic components in
this rabbit model. The in vivo feasibility of this technique permits the serial
analysis of therapeutic strategies on atherosclerotic plaque stabilization.
