Comparative Analysis of Colour Doppler Ultrasonography and CT Angiography in Peripheral Arterial Disease: Studying effects of Vessels Wall Calcification on Diagnostic Evaluation

Introduction: Peripheral Arterial Disease (PAD) is one of the most common causes of morbidity in diabetes mellitus in Indian population. Aim: To analyse comparative role of CDUS (Colour Doppler Ultrasonography) and CTA (Computed Tomography Angiography) in evaluation of PAD and to evaluate impact of vascular calcification on disease assessment as well as predictors for the same. Materials and Methods: A prospective study was conducted on 40 patients having risk factors as well as signs and symptoms of PAD undergoing CDUS followed by CTA. A comparative analysis of arterial system was done by both gray scale and colour spectrum doppler analysis on CDUS as well as by CTA for luminal narrowing or thrombosis, vascular calcification as well as distal flow pattern using Chi-square test. Results: A total of 510 arterial segments were studied by CDUS and 560 by CTA. Luminal irregularity and 50% stenosis and occlusions were better seen on CTA. The false positive cases on CTA were attributed to vascular calcification and areas of eccentric stenosis, whereas false positive cases on CDUS were seen in anatomical complex locations and in cases of proximal long segment stenosis. Significant statistical difference exists between CDUS and CTA. The overall sensitivity, specificity and accuracy of CDUS as compared to CTA in our study were 91%, 87% and 89%. Conclusion: CDUS can be used as first line investigation for evaluation of PAD especially in femoropopliteal segments, low grade stenosis and eccentric stenosis. CTA on the other hand, is more sensitive in detecting segments of total occlusion and infrapopliteal segments.