Investigation

Several investigations are available to evaluate carotid stenosis.

• duplex doppler ultrasonography
  • usually the first diagnostic imaging method used
  • detects calcification of carotid-artery plaque and intraplaque hemorrhage and can measure the degree of stenosis
  • relatively inexpensive and non invasive
  • has a sensitivity of 86% and a specificity of 87% for the detection of hemodynamically significant carotid artery stenosis
• computed tomographic angiography
  • provides good resolution of entire vascular tree - the carotid arteries from the aortic arch to the circle of Willis with 100% sensitivity and 63% specificity
• magnetic resonance angiography
• catheter angiography (1,2,3)

Other investigations should be for vascular risk factors and other causes of stroke - FBC, ESR, U+E's, blood sugar, serum cholesterol, serology for syphilis, ECG and CXR. Echocardiography to exclude a cardiac source of embolism or a CT in patients with TIA to exclude an intracranial lesion, may be warranted.

Carotid and vertebral angiography should be used only to confirm the results of non-invasive screening and to determine the degree of stenosis for possible surgery.

Reference:

• (1) Thapar A et al. Diagnosis and management of carotid atherosclerosis. BMJ. 2013;346:f1485.
• (2) Cleveland clinic. Centre for continuing education. Disease management. Carotid artery stenosis (2016).
• (3) Lanzino G, Rabinstein AA, Brown RD Jr. Treatment of carotid artery stenosis: medical therapy, surgery, or stenting? Mayo Clin Proc. 2009;84(4):362-87; quiz 367-8.