Clinical value of dipyridamole brain perfusion imaging in the diagnosis of ischemic cerebrovascular disease

Objective: Using dipyridamole stress test to evaluate cerebral blood flow reserve in cerebrovascular disease (CVD). Methods: There were 8 normal subjects and 66 CVD patients included. Dipyridamole (0.14 mg·kg-1·min-1) was given intravenously at 4 min before injection of 99Tcm-ECD, then the brain SPECT scanning was performed after 30 minutes. The baseline SPECT images were obtained under similar conditions 2-5 days later. The images were analyzed qualitatively and semi-quantitatively. Results: By visual and semi-quantitative analysis, the responses of cerebral blood flow to dipyridamole were divided into the following four patterns: A: The dipyridamole SPECT showed an expanded area of hypoperfusion, Asymmetry Index (AI) and Uptake Rate (UR) were all decreased; B: Rest image was normal but new hypo-perfused areas appeared on stress test with decreased AI and UR; C: Hypo-perfused areas were decreased in size or disappeared after stress test with increased AI and UR; D: No changes showed in cerebral perfusion imaging patterns, and in AI and UR between stress and rest studies. 14 patients had a cross cerebellar diaschisis (CCD) which became normal after dipyridamole test. Conclusion: Dipyridamole brain perfusion imaging may be helpful to the diagnosis of CVD, to the decision of therapeutic plan, and to predicting the therapeutic effect