Objective To evaluate the appl ication of CT perfusion in intra-axia l disease. Methods By applying a nuclear medicine data processi ng technique to the time-density data obtained from dynamic CT, cerebral tissue perfusion was p e rformed in 8 cases, 4 with normal findings, 2 with ischemic cerebrovascular dise ase, and 2 with gliomas. Cerebral blood perfusion maps was created and analyzed, absolute regional cerebral blood volume, regional cerebral blood flow, and mean transit time were determined and analyzed as well. Results Wit h regard to var ious degrees of perfusion impairment within the ischemic territory, thus giving rise to a very heterogenous appearance. As a rule, the center of a lesion usuall y representing the core of ischemia showed marked reduction of blood flow. At th e outer margin of a tumor area, the reduction of CBF and CBV was often less pron ounced, indicating some residual flow via collaterals, as was confirmed by the b olus delay on the time to peak time. Conclusion In the near fut ure, functional imaging techniques should have a major impact on therapeutic decision-making i n acute stroke patients, perfusion CT may be recommended even now for emergency applications in daily patient care due to its practicability.