Transcranial color Doppler sonography as an alternative tool for evaluation of terminal internal carotid artery steno-occlusion in moyamoya disease

Objective To investigate color Doppler ultrasonography criteria and its value in assessing the steno-occlusion of the terminal internal carotid artery in moyamoya disease. Methods According to the digital subtraction angiography findings, patients were divided into three groups: occlusion of the terminal internal carotid artery, >50% stenosis, and <= 50% stenosis. We measured the terminal and proximal internal carotid artery parameters of each group using transcranial and cervical color Doppler sonography. Results Blood flow signals in 12 terminal internal carotid arteries were absent, which were verified as occlusion by digital subtraction angiography. Parameters were obtained in the remaining 159 terminal/proximal internal carotid arteries to predict cutoffs for >50% stenosis and occlusion. For >50% stenosis, mean flow velocity >88.50 cm/s in the terminal internal carotid artery could achieved the highest receiver operating characteristic curve area of 0.776 with 62.50% sensitivity, 88.15% specificity, 48.39% positive predictive values, 92.97% negative predictive value, and 84.27% overall accuracy. For the occlusion, mean flow velocity <49.50 cm/s in the terminal internal carotid artery achieve the highest receiver operating characteristic curve area of 0.734 with 55.56% sensitivity, 83.81% specificity, 63.83% positive predictive values, 78.57% negative predictive value, and 74.21% overall accuracy. The area under receiver operating characteristic curve cutoffs for other parameters were less than 0.7. Conclusion Mean flow velocity of terminal internal carotid artery provides useful diagnostic information for detecting steno-occlusion in moyamoya disease. It may be used as an alternative tool to evaluate steno-occlusion of the terminal internal carotid artery in moyamoya disease.