Abstract
Functional imaging including perfusion study has been feasible in acute cerebral ischemia, which can provide the information of areas of pneumbra or tissue at risk even by MR examination. Pathophysiological significance or clinical usefulness of perfusion-diffusion MRI, however, has not been confirmed because of lack of comparison with experimental inspection or investigation of prediction for risk of thrombolysis. Some methodological drawbacks, i.e., tracer delay effect on dynamic susceptibility-contrast MRI, cause serious underestimation of CBF value in evaluating remediable area on perfusion MRI. Oxygen metabolic imaging by PET would be superior to MRI in detecting areas of evolving infarct in the hyperacute stage of cerebral infarction. Considering these unsolved problems, development of proper correction to improve accuracy of the method with the validation of physiological phenomenon would be needed in the functional MR imaging in the clinical state of the hyperacute stage of cerebral infarction.
