A comparison of non-invasive methods in the assessment of extracranial carotid artery disease.

The accuracy of four-invasive methods used in the evaluation of the extracranial carotid arterial system are presented. Three of the methods were the flow dependent whilst the fourth was an ultrasonic imaging system. A consecutive series of 67 patients, (134 carotid arteries), having carotid angiography were investigated by means of carotid phonoangiography (CPA), oculoplethysmography (OPG), supra orbital Doppler (SOD) and B mode ultrasound scanning. The sensitivity of the B mode ultrasound was 81% with the OPG, CPA and Doppler method yielding sensitivities of 51%, 56% and 63% respectively. The specificity of both the OPG 95% and the Doppler 90% wqs high. The combined use of both B Mode ultrasound and OPG or Doppler will provide an improved overall accuracy in the assessment of extra cranial carotid stenosis.