Correlation of the Computed Tomography Angiography Data with the Clinical Neurological Presentation in Case of Small Degree Stenosis of Internal Carotid Arteries

Purpose. To carry out the correlation of the lumen structure of internal carotid artery (ICA) to the neurological symptoms in patients with small-intermediate (30–69%) degree stenosis based on multislice computed tomography angiography (MSCTA) data; evaluate potential embologenicity of atherosclerotic plaques in patients with small-intermediate stenosis of ICA.

Materials and methods. The data of 49 patients with 30–69% stenosis of ICA were evaluated, 43 (87.8%) men and 6 (12.2%) women; age varied from 51 to 78 years (medium age 59.8 ± 12.2 years). Depending on neurological presentation, patients were divided into 4 groups, according to academician A.V. Pokrovsky classification of cerebro-vascular insufficiency (1979). All patients underwent CTA on the apparatus Toshiba Aquilion One. The CTA data was transferred to the Vitrea workstation for the analysis. Following 3D-recontractions were used: MIP –Maximal Intensity projection, MPR – Multi-Planar Reconstruction, SSD – Shaded Surface Display. Along with estimation of the lumen shape, attention was paid to the presence of ulcerations, which appeared as the indentation of the contour and/or as a plaque with multiple hollows or cavernous appearance.

Results. Mean stenosis degree appeared to be 59.7% in all 49  patients (stenosis index varied from 36% to 67%). In 27  asymptomatic patients mean value of stenosis was 57.8%, in case of discirculatory encephalopathy – 59.6%, in case of transient ischemic attack (TIA) – 60.1%, and in 2 patients with stroke – 62.4%. Based on the analysis of the CTA in 23 (46.9%) cases plaque surface was irregular (Type II and II ulceration prevailed). Type I ulcerations were noted in 5 (10.2%), type II –in 11 (22.4%) and type III – in 7 (14.2%) cases. CTA images showed circular lumen in 15 (30.6%) patient, elliptic lumen in 19 (38.8%) patients, semicircular lumen was seen in 65(12.2%) cases and multilobular – in 9 (18.3%) cases. Correlation of the lumen structure with the clinical presentation showed prevalence of cases with irregular lumen contours in patients with symptomatic cerebral ischemia: impairment of cerebral circulation was seen in 1 out of 15 (6.7) circular narrowings, in 1 out of 19 (5.2%) elliptic narrowings, in 5 out of 9 (55.6%) multilobular and in 2 out of 6 (33.3%) semicircular narrowings.

Conclusion. Asymmetric lumen of ICA revealed by MSCTA with the bigger probability is connected to the presence of ipsilateral symptomatic ischemia, including transient amavrosis, TIA and ischemic stroke. Our study showed, that evaluation of ICA lumen morphology makes possible to reveal patients with increased risk of focal disturbance of brain circulation in case of small-intermediate degree (30–69%) of stenosis.

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