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 between the internal carotid systolic velocity (ICSV) at the carotid bulb and the distal internal carotid systolic velocity (DICSV) for the detection of carotid artery stenosis.

SUBJECTS AND METHODS

Two hundred eleven patients were enrolled in a prospective 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) ratio, and internal carotid (end) 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 improved 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 ICSV/DICSV ratio allowed for a better angiographic correlation for identifying 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.