Digital image display manipulation and observer variability in pediatric chest radiograph interpretation

Background: Interpretation of pediatric chest radiographs is subject to observer variability, and digital image processing may further influence visual assessment. We evaluated interobserver agreement and the effect of controlled contrast manipulation on the interpretation of pediatric chest radiographs. Methods: Sixty anonymised pediatric chest radiographs, comprising 30 classified as normal and 30 as abnormal, were presented in three display conditions: original (OI), contrast-reduced (CRR), and contrast-enhanced (CER). Five pediatricians independently assessed all 180 image presentations for image quality, radiographic features, and final interpretation as normal or abnormal. Interobserver agreement was assessed using Fleiss' kappa and intraobserver consistency using Cohen's kappa. Display-related changes in abnormal and lung-opacity assessments were compared at the underlying radiograph level using paired Wilcoxon signed-rank tests. Results: Overall interobserver agreement for final interpretation was moderate (κ=0.528), with complete agreement in 48.3% of presentations. Agreement was κ=0.496, 0.594, and 0.479 for OI, CRR, and CER, respectively. Among radiographs classified as normal, lung-opacity identification increased from 8.7% with OI to 32.7% with CRR (p=0.012) and 27.3% with CER (p=0.018). Final normal/abnormal classification did not differ significantly between display conditions. Conclusions: Controlled contrast manipulation influenced recognition of lung opacity despite unchanged underlying radiographic content. Standardised display conditions and awareness of perceptual variability may be important in pediatric chest radiograph interpretation.