USE OF COMPUTED TOMOGRAPHY FOR INVESTIGATION OF HEPATIC LIPIDOSIS IN CAPTIVECHELONOIDIS CARBONARIA(SPIX, 1824)

Abstract

Computed tomography is a sensitive and highly applicable technique for determining the degree of radiographic attenuation of the hepatic parenchyma. Radiodensity measurements of the liver can help in the diagnosis of hepatic lipidosis in humans and animals. The objective was to investigate the presence of hepatic lipidosis in captive red-footed tortoises (Chelonoidis carbonaria) using computed tomography. Computed tomography was performed in 10 male red-footed tortoises. Mean radiographic attenuation values for the hepatic parenchyma were 11.2±3.0 Hounsfield units (HU). Seven red-footed tortoises had values lower than 20 HU, which is compatible with C. carbonaria hepatic lipidosis. These results allowed an early diagnosis of the hepatic changes and suggested corrective measures regarding feeding and management protocols.

Contrast-enhanced computed tomography of the liver, gall bladder and urogenital tract in female red-eared terrapins (Trachemys scripta elegans)

“…Chronic liver disease taking the form of steatosis to fibrosis, necrosis or neoplasia (Jacobson 2007), is a common problem in captive chelonians (McArthur 2004;McArthur et al 2004;Campbell 2014;Marchiori et al 2015). Some authors report that fatty liver disease decreases the organ density from 50-70 HU to -10--40 HU (Wilkinson et al 2004;Kiefer and Pees 2011).…”

“…Gumpenberger (2011) defined a fatty liver in the Hermann's tortoise as one with a density of lower than 20 HU. Marchiori et al (2015) performed CT in 10 male red-footed tortoises. Mean radiographic attenuation values for the hepatic parenchyma were 11.2 ± 3.0 HU and seven male tortoises had values lower than 20 HU, which was considered compatible with hepatic lipidosis.…”

“…Studies using different methods of diagnostic imaging for diagnosis of organ function in chelonians have been published (Rubel and Kuoni 1991;DeShaw et al 1996;Hernandez-Divers and Hernandez-Divers 2001;Hernandez-Divers and Lafortune 2004;Wilkinson et al 2004;Silverman 2006;Gumpenberger 2011). Computed tomography (CT) is broadly applied as a diagnostic imag- ing method and is valuable in the characterisation of several diseases in chelonians (Gumpenberger and Henninger 2001;Gumpenberger 2002;Gumpenberger and Filip 2007;Marchiori et al 2015;Spadola et al 2016). The quantitative assessment of tissue density is expressed in Hounsfield units (HU, Kiefer and Pees 2011;Wyneken 2014;Marchiori et al 2015).…”

“…Computed tomography (CT) is broadly applied as a diagnostic imag- ing method and is valuable in the characterisation of several diseases in chelonians (Gumpenberger and Henninger 2001;Gumpenberger 2002;Gumpenberger and Filip 2007;Marchiori et al 2015;Spadola et al 2016). The quantitative assessment of tissue density is expressed in Hounsfield units (HU, Kiefer and Pees 2011;Wyneken 2014;Marchiori et al 2015). The slow respiratory rate in chelonians limits any possible artefacts caused by movement of lungs to minimum, but sedation or short-acting anaesthesia is necessary to prevent the risk of movement artefacts (Mans et al 2013).…”

Hepatic CT attenuation differs in three species of freshwater turtles and hepatic Hounsfield units increase with folliculogenesis in wild Blanding's turtles (Emydoidea blandingii)

“…Currently there are few reports that evaluate attenuation in wild freshwater turtle species or assessment of differences between species, which limits our knowledge of species‐specific variation . Necropsy is the most reliable method to diagnose hepatic lipidosis . Although abnormal blood serum measurements of aspartate aminotransferase (AST), gamma‐glutamyltransferase, alkaline phosphatase, alanine transaminase, and lactate dehydrogenase can all be suggestive of hepatic lipidosis, many of these parameters are not tissue‐specific enzymes exclusive to the liver in turtles and other reptiles, and thus cannot provide a specific diagnosis of hepatic lipidosis .…”