Evaluation of Anterior Cerebral Artery Flow Abnormalities on Transcranial Doppler Ultrasonography

ABSTRACT

BACKGROUND: Anterior cerebral artery (ACA) flow abnormalities on a transcranial Doppler ultrasonography (TCD) represent various conditions, which include hyperemic collateral to the ipsilateral middle cerebral artery (iMCA) or contralateral internal carotid artery (cICA) pathology, and ipsilateral anterior cerebral artery (iACA) stenosis. However, studies related to these conditions have rarely been done. We evaluated the hemodynamic significance of ACA flow abnormalities on TCD without angiographic information. METHODS: We analyzed TCD records, which were recruited consecutively during a 10-month period in our laboratory. ACA abnormalities on TCD were defined as follows 1) mean flow velocities (mFV) of ACA>80 cm/sec; 2) ipsilateral mFV ACA/MCA> 1.2; 3) anterior cerebral artery veloci-ty ratios (ACAVR)> 1.34. We then correlated TCD patterns with a magnetic resonance angiography (MRA) or trans-femoral cerebral angiography (TFCA). RESULTS: Thirty-five patients were recruited to participate in this study. Based on MRA or TFCA, we found 4 patterns of vascular status which could explain the ACA abnormalities on the TCD. The iMCA pathology was demonstrated in 14 cases, cICA pathology in 11 cases, iACA stenosis in 3 cases, and cACA hypoplasia in 5 cases. Eight cases did not show any vascular pathology. CONCLUSIONS: ACA flow abnormalities should be evaluated with absolute flow velocity indicies, as well as other indexes, which mostly signify hyperemic collateral flow to the iMCA or cICA steno-occlusion. (J Korean Neurol Assoc 19(4)349~353, 2001)