Accuracy and reliability of tele-ultrasonography in detecting gastrointestinal obstruction in dogs and cats

Abstract

Objectives: To assess the accuracy and interobserver agreement of tele-ultrasonography for the diagnosis of gastrointestinal obstruction in small animals by radiologists with different levels of experience.

Materials and methods: A retrospective cross-sectional study including dogs and cats admitted with gastrointestinal signs, between 2017 and 2019, that had abdominal ultrasonographic (US) examination performed and images saved for review. Patients were classified into two categories based on final diagnosis: animals with or without complete or partial gastrointestinal obstruction. Observers with four experience levels interpreted the archived ultrasound examinations, simulating a tele-ultrasonography consultation. Analyses of accuracy, sensitivity, specificity, positive and negative predictive values were obtained for each observer for detection of gastrointestinal obstruction. Agreement between observers for the gastrointestinal obstruction diagnosis was assessed using Fleiss's Kappa statistics.

Results: Ninety patients with gastrointestinal signs were included. Of these, 23 of 90 had partial or complete gastrointestinal obstruction. Interpretation of the images by observers via tele-ultrasonography showed intervals of accuracy, sensitivity, specificity, positive and negative predictive values, respectively, of 78.9% to 87.8%, 73.9% to 100%, 77.6% to 89.6%, 55.9% to 70.8% and 90.9% to 100% for diagnosis of gastrointestinal obstruction. Agreement for the gastrointestinal obstruction diagnosis across all reviewers was moderate (Kappa 0.6).

Clinical significance: Tele-ultrasonography had good accuracy for detection of gastrointestinal obstruction, however had a rather low positive predictive value and only moderate interobserver agreement. Therefore, this technique should be used with caution in this clinical context, given the potential surgical decision at hand.