Combined use of color duplex ultrasonography and B-flow imaging for evaluation of patients with carotid artery stenosis.
OBJECTIVE
Color duplex ultrasonography (CDU) is a standard method of noninvasive evaluation of internal carotid artery stenosis (ICAS). B-flow imaging (BFI), on the other hand, is a newer method. We investigated the accuracy of the two noninvasive tests--CDU and BFI--each separately and as a combination of the two tests by comparing with digital subtraction angiography as a reference standard.


METHODS
We performed CDU, BFI, and digital subtraction angiography on 95 consecutive patients with ICAS. Separate and combined test results of CDU and BFI were compared with digital subtraction angiography results.


RESULTS
For identifying 70% to 99% ICAS, as CDU criterion, the ratio of internal carotid artery to common carotid artery peak systolic velocity had the highest diagnostic accuracy (sensitivity, 94%; specificity, 96%). The sensitivity and specificity of BFI were 65% and 98%, respectively. With CDU and BFI, results were concordant in 144 (89%) cases for 70% to 99% ICAS. Sensitivity and specificity of combined CDU and BFI results for identification of ICAS were 95% and 99%, respectively. The misclassification rates of CDU and BFI were 4.7% and 8.1%, respectively. When combined test results were concordant, the misclassification rate decreased to 1.4%.


CONCLUSIONS
CDU showed a slightly better accuracy than did BFI in the diagnosis of carotid artery stenosis. Combined use of CDU and BFI is more accurate than use of either test alone.
Tola
Muharrem
M
Department of Radiology, Türkiye Yüksek Ihtisas Hospital, Kizilay Sokak No: 4, 06100 Sihhiye, Ankara, Turkey.
Yurdakul
Mehmet
M
Cumhur
Turhan
T
D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D001783:Blood Flow Velocity; D002339:Carotid Arteries / Q000503:physiopathology; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging*; D002533:Cerebral Angiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012212:Rheology / Q000379:methods*; D012680:Sensitivity and Specificity; D013599:Systole; D014463:Ultrasonography / Q000379:methods* / Q000592:standards; D018615:Ultrasonography, Doppler, Color / Q000592:standards