The value of internal carotid systolic velocity ratio for assessing carotid artery stenosis with Doppler sonography

OBJECTIVE. The purpose of this study was to assess the value of the ratio b etween the internal carotid systolic velocity (ICSV) at the carotid bulb an d the distal internal carotid systolic velocity (DICSV) for the detection o f carotid artery stenosis. SUBJECTS AND METHODS. Two hundred eleven patients were enrolled in a prospe ctive study comparing several Doppler measurements with carotid angiography . The following spectral measurements were obtained with Doppler sonography : ICSV/DICSV ratio, ICSV, ICSV/common carotid systolic velocity (CCSV) rati o, and internal carotid tend) diastolic velocity (ICDV). Receiver operating characteristic curves were generated for two groups: the first group being 365 carotid arteries for which all Doppler measurements were successfully obtained and the second being a subgroup of 258 carotid arteries for which an ICSV of 100 cm/sec or greater was present. RESULTS. In the group of 365 carotid arteries, the ICSV/DICSV ratio improve d the detection of stenosis of 60% or greater as compared with the ICDV (p =.03). In 258 carotid arteries with an ICSV of 100 cm/sec or greater, the I CSV/DICSV ratio allowed for a better angiographic correlation for identifyi ng stenoses of 60% or greater and 70% or greater as compared with ICSV (p = .006 and .023, respectively), ICSV/CCSV (p =.0013 and .003, respectively), and ICDV (p = .0015 and .020, respectively). CONCLUSION. Using the ICSV/DICSV ratio for the Doppler detection of carotid artery stenosis is advantageous when the ICSV is 100 cm/sec or greater.