Evaluation of a semi-automated computer algorithm for measuring total fat and visceral fat content in lambs undergoing in vivo whole body computed tomography. (October 2017)

• Record Type: Journal Article
• Authors: Rosenblatt, Alana J.; Scrivani, Peter V.; Boisclair, Yves R.; Reeves, Anthony P.; Ramos-Nieves, Jose M.; Xie, Yiting; Erb, Hollis N.
• Is Part Of: Veterinary journal. Volume 228(2017)
• Page Start: 46
• Page End: 52
• Publication Date: 2017-10
• Subjects: Lamb -- Body fat -- Carcass analysis -- Computed tomography -- Semi-automated computer algorithm; Veterinary medicine -- Periodicals; 636
• DOI: 10.1016/j.tvjl.2017.10.012
• Languages: English
• ISSNs: 1090-0233

Abstract

Highlights: Body fat in lambs was measured by computed tomography (CT), carcass dissection and proximate (chemical) analysis. Proximate analysis and semi-automated CT measures of body fat were not interchangeable. Semi-automated CT computer measures of body fat were repeatable. Whole body CT may be used for assessing relative fat content changes in lambs. Whole body CT imaging may be beneficial to assess fat depots in different locations. Abstract: Computed tomography (CT) is a suitable tool for measuring body fat, since it is non-destructive and can be used to differentiate metabolically active visceral fat from total body fat. Whole body analysis of body fat is likely to be more accurate than single CT slice estimates of body fat. The aim of this study was to assess the agreement between semi-automated computer analysis of whole body volumetric CT data and conventional proximate (chemical) analysis of body fat in lambs. Data were collected prospectively from 12 lambs that underwent duplicate whole body CT, followed by slaughter and carcass analysis by dissection and chemical analysis. Agreement between methods for quantification of total and visceral fat was assessed by Bland–Altman plot analysis. The repeatability of CT was assessed for these measures using the mean difference of duplicated measures. When compared to chemical analysis, CT systematically underestimated total and visceral fat contents by more than 10% of the mean fat weight. Therefore, carcass analysis and semi-automated CT computer measurements were not interchangeable for quantifying body fat content without the use of a correction factor. CT acquisition was repeatable, with a mean difference of repeated measures being close to zero. Therefore, uncorrected whole body CT might have an application for assessment of relative changes in fat content, especially in growing lambs.