From the early macrovascular changes to the occlusion of the carotid artery. The role of ultrasonography in the diagnosis and the management of ischemic stroke

Written by Vastagh Ildikó

Cerebrovascular diseases are still the leading causes of morbidity and mortality in all countries of the world. Ischemic stroke caused by atherosclerosis represents 45% of the cases. Large vessel ischemic stroke is most often caused by atherosclerosis. Increased intima-media thickness (IMT) of the large elastic vessels is an early marker of the atherosclerotic process. IMT is examined by B-mode ultrasound between the leading edge of the first (lumen-intima interface) and the second echogenic line (upper layer of the adventitia or media-adventitia interface) in the far artery wall at the highest image quality. The FDA (Food and Drug Administration, USA) has recently accepted that the change in progression of IMT is an index of improvement in vascular risk. Using six fundamental Doppler criteria (the systolic peak velocity, the end diastolic velocity, the spectrum of the wave, the poststenotic flow, the index of internal / common carotid artery and the diameter of residual lumen), it is possible to establish the degree of the carotid artery obstruction and compare that to angiographic results. Vascular imaging should be performed shortly after TIA or stroke to identify the patients of symptomatic arterial stenosis who could benefit from endarterectomy or angioplasty. The most sensitive and specific among the non-invasive imaging modalities in carotid artery stenosis is the contrast-enhanced MRA, closely followed by Doppler ultrasound and CTA, while the non-contrast MRA is the least reliable technique. Digital subtraction angiography may be needed in some cases, for example when other tests have been inconclusive. Carotid artery reconstruction should be indicated after TIA or after stroke with mild residual signs and significant stenosis. The conservative therapy is the administration of antiplatelet therapy and management of vascular risk factors.

 

Keywords: intima-media thickness, duplex sonography of carotid, degree of the carotid artery stenosis, carotid artery reconstruction.


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