No abstract

Abdominal aortic aneurysms (AAAs) are localized pathological vessel dilations and are the 13th leading cause of death in the U.S. While AAA expansion in patients is traditionally assessed with 2D ultrasound by measuring transverse diameters, recent advancements in ultrasound techniques now make it feasible to quantify AAA volumes noninvasively. High frequency ultrasound (typically up to 40 MHz) is ideal for rodent imaging when investigating experimental aneurysms. The purpose of this study was to use 3D ultrasound to measure aneurysm progression in the apolipoprotein-E-deficient (apoE-/-)/angiotensin II (AngII) mouse model that create suprarenal dissecting aneurysms. High frequency ultrasound (40 MHz, Vevo2100, VisualSonics) was used to collect images from C57BL/6 apoE-/- mice infused with AngII from subcutaneously implanted osmotic mini pumps (1000 ng/kg/min) for 28 days (n=6). We could clearly visualize, segment, and quantify 3D volumes of AAAs and visualize the dissection between medial and adventitial layers. Total AAA volume increased steadily at an average rate of 0.51±0.32 mm3/day (mean±SE) between days 3 and 14 after aneurysm formation (Figure 1). This is similar to the increase in false lumen expansion (0.42±0.30 mm3/day), but higher than the true lumen expansion that remained relatively constant over 14 days (0.09±0.06 mm3/day). These data suggest that 3D ultrasound is a technically feasible measure of aortic volume and has utility in evaluating the efficacy of therapeutic agents in animal models.

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