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 m icrovascular network blood flow using the geographic information systems (G IS) technology. ANET enables us to automatically collect and display topolo gical, structural, and functional parameters and simulate blood flow in mic rovascular networks. The user-definable programming interface was used for the manipulation of drawings and data. Visual enhancement techniques such a s color can be used to display useful information within a network. In ANET the network map becomes a graphical interface through which network inform ation is stored and retrieved and simulations of microvascular network bloo d flow are carried out. We have used ANET to study the effects of ionizing radiation on normal tissue microvascular networks. Our results indicate tha t while vessel diameters significantly increased with age in control animal s they decreased in irradiated animals. The tortuosity of irradiated vessel s (16.3+/-1.1 mean+/-standard error of the mean) was significantly differen t 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+/-0.6 s) and irradiated (10.7+/-5.7 s) microvascular networks at 30 days postirradiation. ANET provides an effective tool for handling the large vo lume of complex data that is usually obtained in microvascular network stud ies and for simulating blood flow in microvascular networks. (C) 1999 Biome dical Engineering Society. [S0090-6964(99)00501-9].