Abstract 13223: Evaluation of a New Strain Analysis Program Developed for Small Animal Imaging: Validation Against Sonomicrometry

Abstract

Background: Small animal imaging is an integral part of imaging research. The aim of this study was to test a new motion analysis program developed for very high frame rate 2D images from small animals.

Methods: Ten C57BL/6 mice were subjected to left lateral sternotomies under inhalation anesthesia and continuous monitoring. Two 0.7 mm sonomicrometry crystals were attached along the circumference of the mouse heart. Each mouse was subjected to pharmacological intervention using intravenous infusion of dobutamine (30 ng/gm BW/min) and esmolol (10 mcg/gm BW/min) to change the heart rate no more than 10-15% from the baseline, allowing complete recovery to basal heart rate between and after interventions. Myocardial ischemia was produced by ligating the left anterior descending aorta (LAD) at the end of study. At each steady state, short axis views were acquired using an MS-550S probe on a Vevo 2100 ultrasound system at frame rates >300fps directly from the surface of the heart. Image data was analyzed for circumferential strain in Vevo Strain analysis program.

Results: At each steady state, sonomicrometry derived strain values were lower than echo derived strain, but both showed a strong correlation (r=0.72). Highest strain values were seen with dobutamine infusion, whereas myocardial ischemia with LAD ligation resulted in the lowest peak strain values.

Conclusion: Vevo strain is feasible for strain imaging research using small animals.