Duplex ultrasonography is an efficient diagnostic tool for the detection of moderate to severe internal carotid artery stenosis.
BACKGROUND
The aim of this prospective national multicentre study with 10 participating university and county hospitals was to establish the diagnostic accuracy of carotid duplex sonography in the identification of >or=70% internal carotid artery (ICA) stenosis defined according to European Carotid Surgery Trial (ECST) criteria.


METHODS
In 134 patients, aged 69 +/- 9 years, ICA stenoses were identified by routine carotid duplex ultrasonography, confirmed angiographically within 2 months, and graded according to ESCT criteria. The accuracy of carotid duplex to detect ICA stenosis >or=70% was assessed using receiver operating characteristic (ROC) analysis with carotid angiography as a reference.


RESULTS
Measurement of peak systolic velocity in ICA (PSV(ICA)) identified ICA stenosis >or=70% with high diagnostic accuracy that was Doppler angle dependent resulting in different optimal PSV(ICA) cut points within the angle range 0 degrees -49 degrees (1 x 7 m s(-1)) and 50 degrees -62 degrees (2 x 3 m s(-1)). The diagnostic discrimination was significantly better when narrow Doppler angles (0 degrees -49 degrees ) were used (P<0 x 01) providing the sensitivity of 98 +/- 2% and specificity of 94 +/- 4%.


CONCLUSIONS
Ultrasound duplex technique identifies moderate to severe (>or=70%) ICA stenoses (ECST criteria) with high degree of accuracy that can be further improved by the use of Doppler angle specific optimal PSV(ICA) cut points.
Nowak
Jacek
J
Department of Laboratory Medicine, Division of Clinical Physiology, Karolinska Institutet, Karolinska University Hospital in Huddinge, Stockholm, Sweden. jacek.nowak@ki.se
Jogestrand
Tomas
T
D000368:Aged; D000792:Angiography; D001783:Blood Flow Velocity; D002343:Carotid Artery, Internal; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012372:ROC Curve; D012720:Severity of Illness Index; D018616:Ultrasonography, Doppler, Duplex / Q000379:methods*