Automated quantitative analysis of angiogenesis in the rat aorta model using Image-Pro Plus 4.1

This paper explains the automated image-processing steps for the quantification of microvascular growth formation in the rat thoracic aortic ring model, an ex vivo model using excised rings of rat aorta embedded in a collagen matrix which produce outgrowths of microvessels. This model of angiogenesis is useful to study the mechanism by which external agents inhibit or stimulate endothelial cell proliferation and tube formation. The manual quantification of blood vessel growth in this model is normally a time-consuming, error prone process. Former automated image analysis methods of the ring model are outdated and cannot be used with current software technology. A macro was created using Image-Pro Plus 4.1 software which was chosen for image analysis because it allows a high degree of control and replication of image-processing steps. The accuracy of this macro was determined by comparing automated counts to manual counts in 161 aortic rings. The square root of the manual count versus the square root of the automated count resulted in a root mean square value of 0.8305.