Reliability of carotid doppler performed in a dedicated stroke prevention clinic.
BACKGROUND
Doppler ultrasound (DUS) is used as a screening tool to assess internal carotid artery (ICA) disease. Recent reports suggest that the DUS may be inaccurate in over 28% of patients. We sought to evaluate the accuracy of DUS, when performed in a dedicated stroke prevention clinic (SPC).


METHODS
We retrospectively reviewed the charts of patients who had a DUS performed in our SPC, followed by conventional cerebral angiography. Three groups of patients were defined. Group 1 had DUS measured ICA stenosis of >50%; Group II had a DUS measured ICA stenosis of <50%; Group III had complete ICA occlusion on DUS.


RESULTS
Sixty-seven patients (69 arteries) were included in the study. There were 45 patients in Group I and based on the findings of cerebral angiography, carotid endarterectomy was considered inappropriate in only one patient--a misclassification rate of 2.2% (95% CI: 0 - 6.5%). Group II consisted of 19 patients and on cerebral angiography, none of these patients had a stenosis of >50%--a misclassification rate of 0%. Group III consisted of five patients in whom DUS showed complete ICA occlusion. The angiogram confirmed the occlusion in all five patients--a misclassification rate of 0%. Overall, misclassification rate was 1.45% (95% CI: 0 - 4.3%).


CONCLUSIONS
Doppler ultrasound when performed in a stroke prevention clinic (SPC), has a high accuracy in measuring ICA stenosis of >50%. Doppler ultrasound is reliable in detecting complete ICA occlusion and finally DUS is a reliable screening tool to rule out clinically significant ICA stenosis.
Dean
N
N
Division of Neurology, The Al Owen and Family Stroke Prevention Clinic, University of Alberta, Edmonton, Alberta, Canada.
Lari
H
H
Saqqur
M
M
Amir
N
N
Khan
K
K
Mouradian
M
M
Salam
Abdul
A
Romanchuk
H
H
Shuaib
A
A
D000368:Aged; D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging*; D002533:Cerebral Angiography; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010044:Outpatient Clinics, Hospital; D015203:Reproducibility of Results; D012189:Retrospective Studies; D020521:Stroke / Q000517:prevention & control*; D018608:Ultrasonography, Doppler