Duplex scanning and effect of multisegmental arterial disease on its accuracy in lower limb arteries

Aim: to assess the accuracy of duplex in assessment of peripheral arterial disease and determine the effect of multisegmental disease on the accuracy duplex as opposed to single lesion. Patients and methods: one hundred and seventy-seven lower limbs were examined in 90 patients who presented with lower limb arterial disease, (59 male, 31 female, median age 68 years - 81 with intermittent claudication, eight rest pain, one ulceration). Patients were examined with duplex US, and arteriography (IA DSA). Two radiologists and two technologists were involved in this double-blind study. Patients were classified into five groups; groups with single stenotic lesions, single occlusions, multiple stenotic lesions or occlusions, and multiple mixed disease. Duplex accuracy was determined in each group. Results: duplex was able to differentiate between normal and disease arterial segment with a sensitivity of 92%, specificity 99%, PPV 91%, and NPV 100% and Kappa 0.87. Sixty-six limbs were found to have single lesions, and 68 multisegmental disease. Duplex showed accuracy with a sensitivity of 87%, and specificity of 99%, for single stenotic lesion and 95%, 96% respectively for multisegmental. For single occlusions duplex accuracy showed sensitivity 92% and specificity 100%, and for multisegmental occlusions, sensitivity 97%, and specificity 99%. For mixed multisegmental pathology (stenosis nad occlusion), sensitivity 94% and specificity 97%. Conclusion: duplex is an accurate tool in diagnosis of lower limb arterial disease and multisegmental pathology does not adversely effect this accuracy.