Effect of Body Composition and Age on the Subjective and Quantitative Ultrasound Appearance of the Dogs' Pancreas

Ultrasound assessment of the pancreas in dogs is limited by operator subjectivity and technical variability, particularly when classifying echotexture and echogenicity. This prospective study evaluated quantitative ultrasonographic features of the pancreas in dogs and examined their associations with subjective ultrasonographic features, age, body composition, and technical factors. Seventy-two ultrasounds from client-owned dogs undergoing abdominal imaging for diverse clinical indications between 2016 and 2019 were included. Subjective echogenicity and echotexture were assessed, pancreatic and abdominal adipose thicknesses measured, and quantitative intensity and texture features extracted from regions of interest using image-analysis software. A subset of cases was evaluated by 104 veterinary radiologists in a parallel study to generate consensus classifications used for validation. Multivariable models were applied to assess associations between pancreatic features and age, body weight, adiposity, fat distribution, and technical variables. Mean pancreatic thickness was 10.8 mm (SD 3.1) and was positively associated with body weight. Pancreatic hyperechogenicity was uncommon (8.3%). Quantitative pancreatic intensity was associated with age. Heterogeneous echotexture was common (43%) and, on subjective assessment, was associated with older age and lower transducer frequency. Quantitative texture features were associated with age, pancreatic thickness, pancreas orientation, and transducer frequency. These findings suggest that pancreatic heterogeneity is frequent and age-associated, and that both subjective and quantitative assessments are influenced by technical factors.