[Observer variability in the radiologic interpretation of interstitial lung disease]

To study intra and interobserver variability of two pediatric neumologists in X-ray readings of interstitial lung disease (ILD), to determine the effect of clinical data on the readings, and to evaluate their interpretation in terms of the histopathology diagnosis.

Prospective, cross sectional, comparative, blinded.

The Instituto Nacional de Pediatria of Mexico City.

Chest X-rays of 45 ILD pediatric patients with diagnosis confirmed by open lung biopsy were read by the two observers three times at two weeks intervals and in a randomized fashion. The observers were blinded to previous readings of both observers as well as to the diagnosis. The first two readings were done with no clinical information given to the observers, but some was given for the third reading (age of inception, length of evolution, and main symptoms at time of the X-rays). A classification in one of 5 patterns (lineal, reticular, reticulonodular, grounded glass, honeycomb) was established by the observers. Associations of patterns with anatomopathological diagnosis was explored. Weighted kappa was used in the statistical analysis.

With one exception, good agreement (Kw 0.57-0.88) was found intra and interobservers.

We believe the low variability is the result of the 15 years of shared experience of the two observers participating in this study.