Imaging evaluation of the inferior vena cava.

The inferior vena cava (IVC) is an essential but often overlooked structure at abdominal imaging. It is associated with a wide variety of congenital and pathologic processes and can be a source of vital information for referring clinicians. Initial evaluation of the IVC is most likely to occur at computed tomography performed for another indication. Many routine abdominal imaging protocols may result in suboptimal evaluation of the IVC; however, techniques to assist in specific evaluation of the IVC can be used. In this article, the authors review the spectrum of IVC variants and pathologic processes and the relevant findings from magnetic resonance imaging, angiography, sonography, and positron emission tomography. Embryologic development of the IVC and examples of congenital IVC variants, such as absence, duplication, left-sided location, azygous or hemiazygous continuation, and web formation, are described. The authors detail IVC involvement in Wilms tumor, leiomyosarcoma, adrenal cortical carcinoma, testicular carcinoma, hepatocellular carcinoma, renal cell carcinoma, and other neoplasms, as well as postsurgical, traumatic, and infectious entities (including filter malposition, mesocaval shunt, and septic thrombophlebitis). The implications of these entities for patient treatment and instances in which specific details should be included in the dictated radiology report are highlighted. Furthermore, the common pitfalls of IVC imaging are discussed. The information provided in this review will allow radiologists to detect and accurately characterize IVC abnormalities to guide clinical decision making and improve patient care.