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. 2021 Apr;23(4):357-363.
doi: 10.1177/1098612X20957161. Epub 2020 Sep 22.

CT features of feline lipiduria and renal cortical lipid deposition

Tobias Schwarz  1 , Eimear Shorten  2 , Marisa Gennace  3 , Jimmy Saunders  4 , Maurizio Longo  5 , Fabiano Séllos Costa  6 , Maciej Parys  1 , Danièlle Gunn-Moore  1
Affiliations

CT features of feline lipiduria and renal cortical lipid deposition

Tobias Schwarz et al. J Feline Med Surg. 2021 Apr.

Abstract

Objectives: The aims of this study were to document the presence and prevalence of feline lipiduria and renal lipid deposition on CT, and to search for associations between the presence of lipiduria and sex, urinary tract abnormalities and urolithiasis.

Methods: The CT examinations of 252 cats were reviewed for the presence of an antigravitational hypodense bubble in the urinary bladder with density values between -180 Hounsfield units (HU) and -20 HU. To identify associations between lipiduria and sex, urinary tract abnormalities and urolithiasis, Fisher's exact test was used. Renal cortical density measurement was performed in all cats. The Mann-Whitney test was performed to compare renal cortical density between lipiduric and unaffected cats.

Results: A total of 27 domestic cats (10.7%) had CT evidence of lipiduria. Lipiduric cats had a significantly lower renal cortical density than unaffected cats (P <0.01). Male neutered cats had a significantly higher frequency of lipiduria and lower renal cortical density compared with female neutered cats (P <0.01). There was no significant difference between the groups regarding renal, ureteral or urethral abnormalities.

Conclusions and relevance: Lipiduria is a common physiological phenomenon in cats that can be detected on routine CT examinations. Decreased renal cortical density is associated with lipiduria. This may aid in the diagnosis of feline lipiduria and help to differentiate its presence from other pathological depositions and excretions.

Keywords: CT; fat droplets; fat-fluid level; lipiduria.

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Conflict of interest statement

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Figures

Figure 1
Figure 1
A conscious cat sitting in the VetMouseTrap device, as used for the CT studies
Figure 2
Figure 2
CT images of the urinary bladder of six conscious domestic cats placed in a VetMouseTrap device, showing aggregation of lipid droplets in the most non-dependent part of the urinary bladder lumen, ranging in volume from (a) 0.0236 ml to (f) 0.1214 ml. Only the cats in (c) and (f) are sitting in true sternal recumbency, with the lipid droplets rising to an exact dorsal bladder location. Window width and level were adjusted for illustration purposes
Figure 3
Figure 3
(a) Bar graph showing a significantly higher prevalence of lipiduria in male neutered cats (n = 128) compared with female neutered cats (n = 106). Box plots showing a significantly lower (b) left and (c) right renal cortical density in male neutered cats compared with female neutered cats. HU = Hounsfield unit
Figure 4
Figure 4
Box plots showing a significantly lower median density of (a) the left and (b) the right renal cortex in the lipiduria group (n = 27) compared with the unaffected population (n = 225). HU = Hounsfield unit
See this image and copyright information in PMC

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