[A new parametric image using dynamic SPECT with inhaled 133Xe].

Abstract

As a new parametric image of cerebral lesions, a map of the ratio between regional cerebral blood flow (rCBF) and the 2nd image of a series of dynamic images was proposed and tested. Three classes (poor, mild and well) were defined based on the degree of coupling between the rCBF and the new parametric image of the affected lesion. In 16 patients with cerebral infarction, those in the acute stage (within 1 week after onset) were found to belong to the poor coupling group, and the subacute group (1 to 4 weeks) showed mild coupling. In the chronic group (over 4 weeks), well coupling was observed. All patients of TIA fell into the mild coupling group. In a stimulation study with 5% CO2 mixed air, all of the well or mild-coupled lesions changed to uncoupled. These clinical findings demonstrate the characteristics of the new proposed image.