Comparison of arteriography and noninvasive techniques for the diagnosis of carotid artery disease. A statistical analysis of 140 patients

Abstract

The carotid arteriograms of 140 patients are compared to noninvasive studies performed on the same group using a SAS statistical package for correlation and identity of information obtained. Chi-square and gamma is calculated for all pairs using total number of arteries and also individual sides of the neck. These reveal significant relationship and identity of information for the arteriograms and the Echoflow (continuous wave Doppler imaging) (Diagnostic Electronic Corp.; Lexington, MA). Discrepancies found between the two groups are a higher frequency of normal findings in the arteriograms and a higher frequency of significant stenoses in the Echoflow group. Differences in frequency of occlusion as a diagnosis are difficult to explain because of the time interval between exams. Other noninvasive studies--OPG, wave-form analysis, supraorbital directional flow--showed poor or no correlation and were unreliable for surgical decisions. A comparison of x-ray interpretations (original report, review interpretation, calculated lumen) reveals statistical identity, although there was a 10 per cent variation in those classified as normal and significant stenosis. No attempt was made to determine whether arteriography or Echoflow was more accurate.