title: Radiographic and echocardiographic measurement of the heart in obese cats.
abstract: A prospective study was undertaken to reconcile radiographic cardiomegaly and normal echocardiography in obese cats and to test a radiographic technique for better distinguishing between pericardial fat and the heart. Ten obese, but otherwise normal cats and 10 non-obese normal cats were used. A body condition scoring system was used to objectively group obese and non-obese normal cats. Two-dimensional echocardiograms were made to verify that all cats had a normal heart. Thoracic radiographs then were made using standard and altered exposure techniques. The hearts were measured on these radiographs using the metric and a vertebral scale system. Obese cats consistently had excessive fat around the heart especially if they also had a large amount of falciform fat. Altering exposure technique by increasing mAs and decreasing kVp sometimes enhanced the radiographic contrast between fat and myocardium. Enhanced radiographic contrast accentuated the double silhouette identifying the true cardiac silhouette within the fat expanded silhouette. Pericardial fat usually was distinguished more readily in lateral than in VD radiographs. In two cats, pericardial fat had a characteristic prominent square corner to the right cranial margin of the cardiac silhouette in VD radiographs. Obesity caused increased width and depth of the thoracic cage. 2D echocardiograms revealed normal cardiac dimensions in both groups of cats and increased precordial distance in the obese group.
authors.affiliation: Department of Veterinary Science and Animal Production, University of Queensland, St. Lucia, Australia.
authors.forename: A L
authors.initials: AL
authors.lastname: Litster
authors.forename: J W
authors.initials: JW
authors.lastname: Buchanan
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging*; D000818:Animals; D006332:Cardiomegaly / Q000000981:diagnostic imaging / Q000662:veterinary*; D002371:Cat Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D002415:Cats; D004452:Echocardiography / Q000379:methods / Q000662:veterinary*; D006321:Heart / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D009765:Obesity / Q000000981:diagnostic imaging / Q000662:veterinary*; D011446:Prospective Studies; D013902:Radiography, Thoracic / Q000379:methods; D012016:Reference Values