An investigation into perihilar inflammatory change on the chest radiographs of children admitted with acute respiratory symptoms

Purpose: To determine the incidence, correlation with selected parameters and interobserver variability of radiographic perihilar inflammatory change (PIC) in previously well children under 3 years of age, who were hospitalized with acute respiratory symptoms. Patients and methods: A total of 113 previously well children under 3 years of age who were hospitalized with acute respiratory symptoms, and whose chest radiographs (CRGs) showed no focal pulmonary abnormality, were prospectively identified. The CRGs were read blindly by two radiologists. Each scored the degree of PIC on a five point scale as absent (0), borderline/ equivocal/indeterminate (1), mild but definite (2), moderate (3) and severe (4). Results: PIC was read as definitely present (mean PIC score greater than or equal to 2) in 65 (58%) patients. The mean PIC score correlated with overinflation (r = 0.45, P < 0.01) and patient temperature (r = 0.22, P < 0.05). The mean PIC score was significantly higher (2.1 vs 1.5, P < 0.01) in those receiving antibiotics (n = 69). It was also significantly higher (2.4 vs 1.7, P < 0.01) in those receiving supplemental oxygen (n = 26). PIC was not associated with duration of admission, presence of wheeze (n = 79), use of nebulized bronchodilators (n = 61) or RSV positivity (n = 32). The k value for interobserver variability indicated only fair agreement (k = 0.29) between the two readers on the five point scale and moderate agreement (k = 0.41) when the data was pooled into two groups (0 and 1 vs 2, 3 and 4). Conclusions: PIC is a common radiographic finding in children under 3 years of age who are hospitalized with acute respiratory symptoms. It is positively but weakly correlated with temperature, hyperinflation, antibiotic usage and supplemental oxygen administration. It is subject to substantial interobserver variability.