Diagnostic accuracy of Duplex Ultrasonography versus Multidetector CT Angiography in the Evaluation of Peripheral Arterial Disease of the Lower extremity

Abstract

Background: Peripheral arterial disease (PAD)is a common condition that affects the arteries of the lower extremity. Atherosclerosis is the leading cause of occlusive arterial disease of the lower extremities. Detailed evaluation of peripheral vasculature is an integral part in the management of patients with peripheral vascular diseases. In the present study, we compare the efficacy of Duplex Ultrasonography (DUS) and Multidetector Computed Tomography Angiography (MDCTA) in the evaluation of peripheral arterial disease ofthe lower limb. Materials and Methods: This prospective correlative longitudinal study included 50 patients with clinical suspicion of peripheral arterial disease of the lower limb. Duplex ultrasonography (DUS) was performed as an initial imaging modality followed by MDCT angiography. Arteries were scanned from the level of common femoral artery till the level of dorsalis pedis artery. Imaging findings of DUS and MDCTA were compared with respect to degree of stenosis, length of stenotic segments, vessel wall calcification and to assess collateral circulation.Categorical data was depicted in the form of frequencies and proportions. Chi-square test was used to analyse comparisons between the groups. Continuous data were represented as mean and standard deviation. Results:50 patients with a mean age of 55.76 ± 12.3 years (range between 36-74 years) were evaluated over a period of two years. Diagnostic accuracy of MDCT angiography superseded Duplex Ultrasonography not only in the detection of hemodynamically significant stenosis, but also in the delineation of extent of disease with a p-value < 0.001. Overall diagnostic accuracy of MDCTA in the evaluation of stenosis or thrombosis of popliteal, anterior tibial, posterior tibial, and dorsalis pedis arteries was more than duplex ultrasound with a p-value of less than 0.001. Extent of vessel wall calcification and collateralisation was better delineated on MDCT angiography.The image reconstruction with CT angiography provided better arterial tree delineation and an added advantage over DUS. Conclusion:Duplex ultrasonography can be used as an initial imaging modality followed by MDCT angiography in the evaluation of peripheral arterial disease. MDCT angiography is more sensitive and specific for diagnosis and pre-interventional work-up of PAD, especially in the infra-popliteal segments.