V.1. Clinical and imaging tools
Lung function test in ABPA often shows the features of uncontrolled asthma with airflow obstruction with or without airway bronchodilator reversibility. In HSP a restrictive pattern is often found in combination with a decrease in the carbon monoxide transfer test (91).
Computed tomography of the chest is used to diagnose both ABPA and HSP. In ABPA, central bronchiectasis is a common finding of relatively late onset (92) while in HSP the most common finding is a patched ground glass pattern (91). The limited studies on magnetic resonance imaging (MRI) did not provide evidence for any added diagnostic value of these investigations (93).
Exhaled nitric oxide, a marker of type 2 inflammation, appears to be elevated in cystic fibrosis subjects suffering from ABPA compared with only Aspergillus -sensitized subjects. Therefore FeNO (fractional exhaled nitric oxide) might have a role as a diagnostic test in the context of cystic fibrosis (94).