Takayasu arteritis: ultrasonographic evaluation of the cervico-cerebral arteries

Abstract

Purpose : To present the ultrasonographic findings of the cervico-cerebral arteries in patients with Takayasu arteritis. Materials and methods : We used duplex ultrasound to study the arteries in the neck including the common carotid artery (CCA), internal carotid artery (ICA), external carotid artery (ECA) and the vertebral arteries. For the intracranial arteries, transcranial Doppler ultrasound was used to study the blood flow velocities and directions in the middle cerebral artery (MCA), anterior cerebral artery (ACA), posterior cerebral artery (PCA), ophthalmic artery, basilar and vertebral arteries. The ultrasonographic findings were compared with magnetic resonance angiography (MRA) and standard angiography. Results : Four patients with the diagnosis of Takayasu arteritis were studied. One patient presented with ischemic optic neuropathy and was found to have absent radial pulse. Two patients presented with severe hypertension in young age. The other patient had accidental findings of unmeasurable blood pressure in both arms. One patient had abnormal carotid duplex ultrasound. He was found to have an occlusion of the right ICA. Thickening of the wall of the left ICA was also noted. Reduction of flow velocity in the MCA was demonstrated on TCD. There was evidence of collateral circulation from the contralateral carotid artery demonstrated by reversal of flow in the ipsilateral A1 segment of the ACA. MRA and angiography confirmed the ultrasound findings. Three patients had normal carotid duplex ultrasound but one of them was found to have a severe stenosis at the origin of the common carotid artery by MRA and angiogram. Absence of one vertebral artery was noted in three patients. MRA and angiogram confirmed the occlusion of the same vertebral arteries at their origins. In one patient, reversal of flow in the intracranial part (V4 segment) of the affected vertebral artery indicating collateral flow from contralateral vertebral and basilar arteries was demonstrated. Conclusion : Ultrasonography could be used as an additional noninvasive procedure apart from CT angiography, MRI and MRA in patients with Takayasu arteritis. Occlusion and wall thickening of the neck artery could be detected by color coded B-mode and Doppler ultrasound. Transcranial Doppler was useful in evaluation of flow velocity and flow direction of the arteries around the circle of Willis.