Novel Method to Improve Radiologist Agreement in Interpretation of Serial Chest Radiographs in the ICU

Objectives: To determine whether a novel method and device, called a variable attenuation plate (VAP), which equalizes chest radiographic appearance and allows for synchronization of manual image windowing with comparison studies, would improve consistency in interpretation. Materials and Methods: Research ethics board approved the prospective cohort pilot study, which included 50 patients in the intensive care unit (ICU) undergoing two serial chest radiographs with a VAP placed on each one of them. The VAP allowed for equalization of density and contrast between the patients’ serial chest radiographs. Three radiologists interpreted all the studies with and without the use of VAP. Kappa and percent agreement was used to calculate agreement between radiologists’ interpretations with and without the plate. Results: Radiologist agreement was substantially higher with the VAP method, as compared to that with the non-VAP method. Kappa values between Radiologists A and B, A and C, and B and C were 46%, 55%, and 51%, respectively, which improved to 73%, 81%, and 66%, respectively, with the use of VAP. Discrepant report impressions (i.e., one radiologist's impression of unchanged versus one or both of the other radiologists stating improved or worsened in their impression) ranged from 24 to 28.6% without the use of VAP and from 10 to 16% with the use of VAP (χ2 = 7.454, P < 0.01). Opposing views (i.e., one radiologist's impression of improved and one of the others stating disease progression or vice versa) were reported in 7 (12%) cases in the non-VAP group and 4 (7%) cases in the VAP group (χ2 = 0.85, P = 0.54). Conclusion: Numerous factors play a role in image acquisition and image quality, which can contribute to poor consistency and reliability of portable chest radiographic interpretations. Radiologists’ agreement of image interpretation can be improved by use of a novel method consisting of a VAP and associated software and has the potential to improve patient care.