The Neurology Research Laboratories at Evanston Hospital herein apply for a grant to purchase a General Electric CT/T 8800 Computed Tomographic Scanner. This system will be used exclusively as a research instrument to study bidirectional capillary transport in brain and systemic tumors, to study the formative physiological processes in states causing cerebral edema, and to study capillary transport in other diseases of the nervous system. The principal use of this system is to study drug delivery processes in brain tumors (universally acknowledged to a major limiting factor in the treatment of brain tumors), using techniques that we have already developed in our laboratories. We will also attempt to manipulate drug delivery by changing capillary transport properties, especially with vasoactive amines. In the category of systemic tumors we will concentrate heavily upon ovarian cancer, and will perform the same types of drug delivery studies and manipulations. Both of these cancers are "ideal", since in both disease remains confined locally early in the course and is amenable to local forms of drug delivery manipulation. However, in addition, we will study capillary physiology in multiple sclerosis and stroke, where breakdown of the blood-brain barrier contributes to morbidity and mortality in these diseases. We will develop new methods for measuring the physiological processes contributing to cerebral edema. Throughout these studies we will adhere to a philosophical viewpoint of our laboratories: all studies must first be proven to be efficacious in animal models before they are used in patients. The proposed system is a reconditioned CT scanner. It will be used exclusively for research and will be located adjacent to our laboratories in a new research building. It will enable us to extend new preliminary studies which have been developed with quantitative autoradiography, first to large animal models which can be studied in vivo and over time, and then to eventual application in patients.