Portosystemic shunts in dogs and cats: Imaging portosystemic shunts in small animals - Ultrasonography, nuclear scintigraphy, computed tomography, magnetic resonance imaging

Abstract

Because of the non-specificity of the clinical signs and laboratory findings, imaging techniques such as portography, ultrasonography (US), nuclear scintigraphy, computed tomography (CT), or magnetic resonance imaging (MRI) are required to provide a definitive diagnosis of portosystemic shunts (PSSs). Nuclear scintigraphy is the gold standard for detecting PSSs, but it is not useful in distinguishing the different types of shunts. Due to its high sensitivity, portography has for a long time been considered the gold standard for differentiation of PSSs, despite its invasive nature. However, the recent development of a standard protocol for US and the routine use of Doppler modalities have resulted in the same sensitivity as portography. Therefore, with the additional benefit of being fast and noninvasive, US is now more commonly performed. It may be considered a "new" gold standard, depending upon the experience of the radiologist. Computed tomography and MRI provide detailed anatomic information. In this fourth article about portosystemic shunts in dogs and cats a comprehensive overview of the literature covering US and nuclear scintigraphy will be given. Finally CT and MRI techniques will be explained briefly.