Currently, major effort is devoted to developing and utilizing magnetic resonance (MR) microscopy for in vivo histologic studies of major organs systems in small animals such as rats and guinea pigs. This work takes two directions: 1. development of monitoring and physiologic and support systems and 2. examination of magnetic resonance correlates of the microscopic changes that occur in the lungs, liver, kidneys, brain and blood vessels. MR imaging at microscopic resolution in live small animals presents numerous technical and biologic problems. The animals must be immobile and in a normal physiologic state for minutes to hours requiring anesthesia, vital sign monitoring, and biologic support such as for body temperature. This must be accomplished in the small confines of an imaging magnet and in the presence of strong magnetic and radio frequency fields without direct access to the animal. We have designed equipment and developed procedures for these takes. This has allowed us to examine the effects of various agents on the lungs, liver, kidneys and blood vessels.
