Noninvasive Assessment of Atherosclerosis in Apolipoprotein-E Knockout Mice by Ultrasound Biomicroscopy

Intima media thickness is a marker for human atherosclerosis. This study aimed to validate the hypothesis that atherosclerosis progression in vivo in mice can be visualized noninvasively using high-resolution ultrasound biomicroscopy (UBM), and to study the association between UBM characteristics and plasma lipids in the apolipoprotein-E knockout (ApoE-/-) mouse model. Four age groups of male ApoE-/- mice were used as atherosclerotic models, with age-matched male C57BL/6 mice used as controls. Plaque thickness and area measured by UBM correlated with histologic measurements (r = 0.81, r = 0.70, respectively; p < 0.001). Serum total cholesterol, low density lipoprotein cholesterol and triglycerides were higher in the ApoE-/- groups compared with controls (p < 0.01). Plaque thickness was correlated with total cholesterol (r = 0.505, p < 0.001). High-resolution UBM provides a noninvasive, accurate means of detecting atherosclerosis progression in vivo in mice and can detect changes in the early stage of atherosclerosis.