Author: Amit Mehta, MD, Chief Radiologist, and Susan Hall, CT Technologist,
St. Catharines General Site – Niagara Health System, Ontario, Canada

History

A 68 year old female admitted to our facility for a pre operative assessment for carotid endarterectomy. The patient has experienced episodes of vision loss in the right eye over the past 2 or 3 months, but had no speech difficulties and no motor or sensory deficits have been detected. The patient had a history of a carotid Doppler examination in 2003 at which time she had severe stenosis of both internal carotid arteries (ICA). A Doppler ultrasound in 2006 showed an occluded left ICA and 80– 90 percent stenosis of the right ICA. She also has a history of hypertension and smokes. The CNS exam was grossly intact. A CTA of the carotids was performed for pre-operative assessment.

Diagnosis and Comments

The CTA data confirmed a complete occlusion of the left common carotid and internal carotid arteries. The left external carotid artery is partially reconstituted via a muscular collateral artery. Additionally, a severe stenosis at the bifurcation of the right internal and external carotid artery by a mixed calcified and soft plaque was detected. With the high resolution of SOMATOM Sensation 64 and syngo Neuro DSA the CTA of the whole carotid artery could be displayed and evaluated easily using the automated bone subtraction functionality.

Fig. 1: VRT of the carotid arteries.

Fig. 2: CT digital subtraction angiogram: frontal view. VRT display after automatic substraction of bone using syngo Neuro DSA CT.

Fig. 3: MIP image obtained with the automated subtraction algorithm of syngo Neuro DSA showing occlusion of the left common carotid and internal carotid arteries with severe stenosis of the right internal carotid artery. A muscular collateral fills the left external carotid artery.