Delayed non‐selective contrast‐enhanced CT can reveal spontaneous contrast enhancement of the lymphatic system in cats

Abstract

AbstractThe authors incidentally observed that, on delayed postcontrast CT studies, feline patients could show increased attenuation of the lymphatic system. The aim of the present study was to evaluate if the lymphatic system of feline patients undergoing intravenous administration of contrast medium might consistently enhance on delayed postcontrast CT studies. Feline patients that underwent CT examination for variable diagnostic purposes were included in this multicentric observational descriptive study. A 10‐min delayed postcontrast whole‐body CT series was obtained for all cats enrolled and the following anatomic structures were systematically assessed: mesenteric lymphatic vessels, hepatic lymphatic vessels, cisterna chyli, thoracic duct, and anastomosis of the thoracic duct with the systemic venous system. A total of 47 cats were included in the study. The mesenteric lymphatic vessels showed enhancement in the selected series in 39 of 47 (83%) patients and the hepatic lymphatic vessels in 38 of 47 (81%) patients. The cisterna chyli, thoracic duct, and the point of anastomosis of the thoracic duct with the systemic venous circulation were enhanced in 43 (91%), 39 (83%), and 31 of 47 (66%) cats, respectively. This study confirms the initial observation. The mesenteric and hepatic lymphatic system, the cisterna chyli, the thoracic duct, and its anastomosis with the systemic venous circulation of feline patients undergoing intravenous administration of iodinated contrast medium can show spontaneous contrast enhancement in non‐selective 10‐min delayed contrast‐enhanced CT series.