“The CT findings are suggestive of chronic aspiration”: truth or assumption?

Introduction: In young children undergoing CT Thorax, a dependant right upper and bilateral lower lobe distribution of pathology is often reported as “suggestive of chronic aspiration”. There is little published evidence to support this claim. Aim: To document the nature and prevalence of lung pathology on CT in children under 5 years who aspirate on videofluoroscopy (VF). Methods: On CT, each lobe was scored for the presence of interstitial disease, linear atelectasis, volume loss, mosaic attenuation, ground glass, bronchial thickening, mucus plugging, bronchiectasis and consolidation (9 features). Each feature was scored as present/absent (maximum score 54 i.e. 9x6 lobes). Severity was quantified by thirds of lobe involved (0-3 per lobe). VF studies were scored from 0 (no aspiration) to 5 (aspiration on solids requiring non-oral feeding) and compared to CT scores (Spearman’s). Results: 98 patients underwent VF in 2016. 47 also had a chest CT (median age 2.5years, IQR 1.4-4) with a median interval between VF and CT of 2.5 months (2.5-10). Median aspiration severity score was 2 (1.5-2). Median CT score was 6 (2-10). The right upper lobe was most commonly affected (24% of features), followed by the lower lobes (19% each). The most common features were linear atelectasis (33%), mosaic attenuation (21%) and bronchial thickening (13%). Preliminary data demonstrated no significant correlation between number of features present or their severity and the grade of aspiration on VF. Conclusion: Thoracic CT findings in a group of children with proven aspiration on VF matched the traditional distribution of “chronic aspiration”. There was no significant correlation between the severity of aspiration and the severity of CT findings.