title: Elimination of extracranial blood flow during dynamic cerebral perfusion studies using diffusible and non-diffusible radioisotope.
abstract: The extracranial blood flow seriously complicates the interpretation of dynamic cerebral studies. To eliminate this, we used a blood pressure cuff placed around the head in 50 patients with no evidence of cerebrovascular disease. The pressure in the headband was increased to 30 mmHg above the patient's systolic pressure, and the first 60 sec static scintigram was taken exactly 3 min after the injection of 99mTc-pertechnetate. A second 60 sec static scintigram was taken without pressure in the headband at 6 min after injection. After correction for diffusion of tracer into extravascular compartments we could still show 13% reduction in counting rates over the hemispheric regions and 30% over the convexity regions during application of the pressure headband. With the Xenon method, the application of the headband appears to have insignificant influence on the results of cerebral perfusion. We thus recommend that a headband should be used for dynamic 99mTc-isotope cerebral circulation studies.
mesh_terms: D002560:Cerebrovascular Circulation; D006801:Humans; D010477:Perfusion; D011312:Pressure; D011877:Radionuclide Imaging / Q000295:instrumentation*; D013667:Technetium; D014980:Xenon Radioisotopes
chemical_list: D014980:Xenon Radioisotopes; D013667:Technetium