Relationship between Flow Diversion on Transcranial Doppler Sonography and Leptomeningeal Collateral Circulation in Patients with Middle Cerebral Artery Occlusive Disorder

Flow diversion (FD) has been considered as indirect evidence of intracranial artery occlusion, and it was associated with early improvement in patients with MCA occlusion. It is not known whether FD can represent leptomeningeal collateral circulation or not in patients with middle cerebral artery (MCA) occlusive disorder. FD was defined by increased velocity (> 30%) in anterior or posterior cerebral artery (ACA, PCA) compared to contralateral analogs artery in patients with MCA occlusive disorder. The leptomeningeal collateral channel (LMC) was identified using digital subtraction angiography. A total of 51 patients were enrolled in this analysis. Transcranial Doppler (TCD) showed a FD in 47% (24) of patients. Twenty-three patients had FD in ACA, and 1 patient in PCA. LMC was identified in 41% (21) of patients. Sensitivity of FD for leptomeningeal collateral circulation was 81%, specificity 76.7%, positive predictive value 70.8%, and negative predictive value 85.2%. Presence of FD showed good correlation with presence of LMCs in patients with MCA stenosis (r = .568, P = .00) FD on TCD suggests the presence of leptomeningeal collateral circulation in patients with MCA occlusive disorder. J Neuroimaging 2009;19:23-26.