OBJECTIVETo assess the clinical value of transoral carotid ultrasonography (TOCU) in the detection of the blood flow parameters of the distal extracranial internal carotid artery (ICA) in patients with moyamoya disease.

METHODSFourteen patients with the diagnosis of moyamoya disease confirmed by digital subtractive angiography (DSA) underwent examination with conventional carotid ultrasonography of the proximal internal carotid artery (ICA). TOCU was performed to observe the distal extracranial ICA and the internal diameter, peak systolic velocity (PSV) and end-diastolic velocity (EDV) were measured.

RESULTSAll the patients had unilateral moyamoya disease. Compared with the contralateral ICA, distal extracranial ICA showed a significantly reduced internal diameter, PSV and EDV (P<0.05). No significant differences were found in the internal diameter, PSV or EDV between the distal and proximal ICA on the diseased side. The internal diameter of the bilateral common carotid arteries (CCA) was similar, but the PSV and EDV were significantly lower in the contralateral CCA.

CONCLUSIONTOCU can provide information of the blood flow in the distal extracranial ICA to facilitate an accurate diagnosis of moyamoya disease.