Phonoangiography by autocorrelation

Phonoangiography, as a noninvasive quantitative analysis of arterial bruits, was conducted just prior to standard invasive radiographic angiography in 135 patients. Sound records from 162 carotid arteries were analyzed with a new processing technique employing a high speed analog acoustic analyzer, the autocorrelator. In 18 arteries with carotid stenosis, a correlation coefficient of 0.87 resulted between phonoangiographic diameter predictions and radiographic diameter estimates. Bruit analysis identified two patients with patent lumen diameters, but tortuous carotid vessels. One hundred thirty-three carotid arteries had no bruits that could be analyzed, but angiograms showed no extracranial stenosis. Four arteries from which bruits could not be analyzed were found to be totally occluded. Carotid phonoangiography appears applicable in approximately one of seven patients now requiring angiography of head and neck vessels. When applicable, phonoangiography is significantly correlated with angiographic findings.