A "geographic information systems" based technique for the study of microvascular networks.

An automated system (ANET) has been developed to construct interactive maps of microvascular networks, calculate blood flow parameters, and simulate microvascular network blood flow using the geographic information systems (GIS) technology. ANET enables us to automatically collect and display topological, structural, and functional parameters and simulate blood flow in microvascular networks. The user-definable programming interface was used for the manipulation of drawings and data. Visual enhancement techniques such as color can be used to display useful information within a network. In ANET the network map becomes a graphical interface through which network information is stored and retrieved and simulations of microvascular network blood flow are carried out. We have used ANET to study the effects of ionizing radiation on normal tissue microvascular networks. Our results indicate that while vessel diameters significantly increased with age in control animals they decreased in irradiated animals. The tortuosity of irradiated vessels (16.3+/-1.1 mean+/-standard error of the mean) was significantly different from control vessels (10.0+/-1.3) only at 7 days postirradiation. Average red blood cell transit time was significantly different between control (1.6+/-0.6s) and irradiated (10.7+/-5.7s) microvascular networks at 30 days postirradiation. ANET provides an effective tool for handling the large volume of complex data that is usually obtained in microvascular network studies and for simulating blood flow in microvascular networks.