Interobserver Variability in Applying a Radiographic Definition for ARDS: Chest radiographs
Positive chest radiographs that were interpreted with the greatest agreement had dense alveolar consolidation in all four lung quadrants (Fig 1). Radiographs that were interpreted with high variability had opacities that some readers interpreted as atelectasis and others interpreted as infiltrates, bilateral lower lobe infiltrates, small lung volumes, or overlying monitoring equipment that obscured the pulmonary parenchyma (Fig 2). Pleural effusions also accounted for disagreement when some readers identified infiltrates “behind” the effusion and others did not (Fig 3). Radiographic features that might be consistent with mild pulmonary edema, such as increased interstitial markings, indistinct vessels, and blurring of the hilar structures, were frequently cited by the readers as problematic (Fig 4).
Experts in the field of ALI do not agree when they apply the current consensus radiographic definition for ALI-ARDS. A K-statistic value of 0.55 indicates only moderate agreement. K-statistic values in this range have raised concerns in the interpretation of mammograms, ventilation-perfusion scans, and chest radiographs in community-acquired pneumo-nia.’’ There was full agreement on less than half the radiographs. Chest radiographs that were interpreted consistently as positive were obtained from patients with dense alveolar infiltrates in four lung quadrants. Infiltrates limited to lower lung zones, atelectasis, small lung volumes, mild involvement, pleural effusions, and overlying monitoring devices all were identified as contributing factors for high variability of radiograph interpretations. There was a twofold difference in the positive radiograph rate between the reader least likely to call a radiograph positive (36%) and the reader most likely to call a radiograph positive (71%). natural inhalers for asthma
Figure 1. Chest radiograph with 100% agreement: consistent with AECC radiographic criterion.
Figure 2. Chest radiograph with 71% agreement. The majority of interpretation was inconsistent with ALI-ARDS. Readers commented on low lung volumes and atelectasis complicating interpretation.
Figure 3. Chest radiograph with 86% agreement. The majority of interpretation was inconsistent with ALI-ARDS. Readers commented on the presence of right pleural effusion.
Figure 4. Chest radiograph with 52% agreement. The majority of interpretation was consistent with ALI-ARDS. Readers commented on mild interstitial infiltrates.