Prevalence and Clinical Significance of Incidental Extravascular Findings in Computed Tomographic Angiography of Voluntary Kidney Donors and Patients with Disease of the Aorta and Lower Limb Arteries

INTRODUCTION: For nearly twenty years now, many institutions worldwide have used computed tomographic angiography (CTA) to examine the systemic arterial system in the chest, abdomen, and pelvis. The techniques of CTA have evolved since its advent but the basic principle has remained the same, involving a timed intravenous injection of contrast material, rapid data acquisition and image reconstruction – particularly multiplanar reformation – at narrow intervals. Inherent in the cross-sectional nature of CTA is the advantage, versus conventional angiography, of visualisation of important nonvascular abnormalities as well. Additionally, CTA is also less invasive and expensive than conventional angiography. Therefore CTA is increasingly being employed as a substitute, complementary, or follow-up study to conventional angiography, especially to assess aortic or lower limb arterial disease and variant renal vascular anatomy in potential voluntary kidney donors. This provides a significant number of patients an opportunity to diagnose disorders that otherwise would have been undiscovered until symptoms developed, for example early cancer. AIMS AND OBJECTIVES: 1. To determine the prevalence and profile of incidental extravascular findings in CTAs performed on Indian subjects from the following two groups: a. Voluntary kidney donors (VKDs) undergoing CTA as a part of pre- transplant work-up. b. Patients with suspected aortic or lower limb arterial disease. 2. To determine the prevalence of clinically significant incidental extravascular findings in the same subjects. CONCLUSION: Incidentally detected extravascular findings are fairly common among Indian subjects undergoing CT angiography. However, nearly 90% of these findings are safe to ignore. The prevalence of previously unknown malignancy that is incidentally detected among Indian subjects undergoing CT angiography is lower than that in western populations. Infectious pathologies constitute a significant component of non-neoplastic but serious incidentally discovered and clinically significant extravascular findings at CT angiography. A study on a larger group of Indian patients with arterial disease is recommended to build on the inferences from this study, with respect to the prevalence of malignancy and infectious disease among incidentally detected clinically significant extravascular findings