Limitations of ultrasonic duplex scanning for diagnosing lower limb arterial stenoses in the presence of adjacent segment disease.
OBJECTIVE
The purpose of this study was to provide a quantitative evaluation of the effect of adjacent segment lesions on disease classification in lower limb arteries by ultrasonic duplex scanning.


METHODS
Lower limb arterial duplex scanning from the distal aorta to the popliteal artery was performed in 55 patients. Arterial lesions evaluated by visual interpretation of Doppler spectra were compared blindly with those measured by angiography.


RESULTS
To recognize severe stenoses (50% to 100% diameter reduction) in any arterial segment, duplex scanning had sensitivity and specificity rates of 74% and 96%, respectively. However, sensitivity and specificity rates increased to 80% and 98%, respectively, when there was no 50% to 100% diameter-reducing lesion in adjacent segments, whereas they decreased to 66% and 94%, respectively, when there was at least one 50% to 100% diameter-reducing lesion in adjacent segments. Moreover, among the 48 duplex misclassifications underestimating or overestimating the degree of arterial stenoses, 30 (62.5%) involved a segment with at least one 50% to 100% lesion in adjacent segments. The segments mostly affected by proximal and distal arterial lesions were the popliteal arteries and the common and deep femoral arteries, where it was found that 86% (24/28) of the misclassifications involved the presence of either proximal or distal severe stenoses.


CONCLUSIONS
The results demonstrated that the presence of multiple stenoses was an important limitation of duplex scanning for the detection and quantification of lower limb arterial disease.
Allard
L
L
Laboratoire de Génie Biomédical, Institut de Recherches Cliniques de Montréal, Québec, Canada.
Cloutier
G
G
Durand
L G
LG
Roederer
G O
GO
Langlois
Y E
YE
D001012:Aorta, Abdominal / Q000000981:diagnostic imaging; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging; D005263:Femoral Artery / Q000000981:diagnostic imaging; D006801:Humans; D007083:Iliac Artery / Q000000981:diagnostic imaging; D007866:Leg / Q000098:blood supply*; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000000981:diagnostic imaging*; D011150:Popliteal Artery / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity; D014465:Ultrasonics; D014463:Ultrasonography