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).