Total occlusion of the common carotid artery with patent internal carotid artery. Identification with color flow Doppler imaging.

With common carotid artery occlusion there is usually no flow in the distal vessels. However, flow to the ipsilateral internal common carotid artery may be maintained by collateral vessels. Nine of 1100 patients referred for carotid duplex sonography were found to have occluded common carotid arteries. Five of these patients had collateral circulation with reconstitution of flow via the external carotid artery. The color Doppler sonograms of three representative patients are presented. There was antegrade flow in the internal carotid artery with retrograde flow in the external carotid artery.

Differentiation of detached retina and vitreous membrane with color flow Doppler.

The sonographic criteria for diagnosis of retinal detachment and vitreous membranes are well established, and in most cases a diagnosis can be made. However, in difficult cases, differentiation between the two may be difficult. In this study the use of high-resolution color flow Doppler was evaluated for differentiating between retinal detachments and vitreous membranes. Sonographic evaluation, including color flow Doppler, was performed in 25 symptomatic eyes. Seven eyes had areas of retinal detachment, all of which had detectable blood flow within at least a portion of the detached retina. Fifteen eyes had vitreous hemorrhages or membranes in which no flow was detected. Two diabetic patients with vitreous membranes and no retinal detachment did have flow detectable within the neovascular membranes. Another patient, who had a complete choroid detachment after surgery, demonstrated good flow within the area of detachment. It is concluded that in difficult cases high-resolution color flow Doppler can enable differentiation of an area of retinal detachment from a vitreous membrane in a patient without diabetes.