Relationship of mri pattern of carotid atherosclerotic plaque to cerebrovascular reactivity in carotid stenosis

Abstract

The aim of the study was to compare the structure of atherosclerotic plaques visualized using MRI with cerebral vascular reactivity detected by ultrasound in patients with carotid atherosclerosis. Materials and methods. The patients′ population comprised 21 persons (mean age 64 ± 13) with hemodynamically significant carotid artery stenosis for over 70 % of lumen. All patients underwent MR imaging of the carotid arteries. To assess the cerebrovascular reactivity transcranial ultrasound of middle cerebral artery was done and blood flow parameters were determined during the stress tests: test with breath holding and hyperventilation. Results and discussion. It was found that at test with breath holding there is a statistically significant association between MRI plaque structure and direction of the reaction (p = 0.081), whereas at the test with hyperventilation no significant differences were found. At tests with breath holding in 56 % patients with MR images of plaque hypointense on T1-weighted scans and hyperintense on T2-weighted ones unidirectional positive response was observed; unidirectional negative response or multidirectional response were observed in patients with MR images of plaque hyperintense on T1-weighted scans and hypointense on T2-weighted ones. Conclusion. Atherosclerotic lesions of the internal carotid artery with intra-plaque hemorrhage are accompanied by critical deterioration of cerebrovascular reactivity. Thus, every hemorrhage to carotid plaque is critical risk factor and requires removal of the plaque by carotid endarterectomy. Such study may be suggested as a screening test in all patients of risk groups of atherosclerosis.

Keywords

• carotid atherosclerosis
• сarotid arteries
• mri
• stroke risk
• сerebrovascular reactivity