Independent bone-level diagnostic accuracy study of an AI tool for detecting appendicular skeletal fractures on radiographs
摘要
To perform an in-depth evaluation of the diagnostic test accuracy of a commercially available AI tool for assistance in fracture detection on radiographs.
Materials and methodsThis retrospective study included consecutive patients with trauma radiographs at seven Danish hospitals. The AI output was evaluated using the clinical radiologic report as a reference standard for a binary fracture outcome. The report is based on assessments by an emergency physician, a senior orthopedic surgeon, and a radiology expert. Sensitivity, specificity, positive- and negative predictive values were calculated. Sensitivity and specificity were additionally stratified for children, degenerative disease, metal, old fractures, casting, obvious fractures, and inter-hospital differences. Bone-wise sensitivity and specificity were assessed for multiple fracture cases and individual bones.
ResultsThe study sample consisted of 2783 patients (median age 38 years, IQR, 21, 64, 1443 female), and 948 (34%) had the target finding. The AI tool demonstrated an overall sensitivity of 89% (95% CI: 87%–91%) and specificity of 88% (95% CI: 86%–89%). The specificity was 57% (95% CI: 49%–65%) in examinations with old fractures. Bone-wise sensitivity for carpal fractures ranged from other carpals 25% (95% CI: 1%–81%] to triquetrum 75% (95% CI: 43%–95%). Tarsal fractures ranged from medial cuneiform 0% (95% CI: 0%–60%) to talus 53% (95% CI: 27%–79%).
ConclusionThe AI tool demonstrated high overall diagnostic accuracy and performed robustly across most specific situations. However, specificity was substantially reduced in the presence of old fractures. The bone-wise analysis showed great variability, with a pattern of poor accuracy for short, irregular bones.
Key Points