CT of the chest is the more definitive study and should reassure you that no suspicious lung abnormality was identified. Plain radiographs are a two dimensional evaluation of a 3D structure (your body) and, as a result, there is superimposition of soft tissue structures within the chest which may mimic a nodule in the lungs. Apical pleural thickening is a relatively common finding on imaging in the general population and is unlikely to be due to mould exposure but it would be worthwhile to complete a screen for allergen exposures and to determine any exposure risks in your environment.

Thanks, Paul Gibson MD.

Paul E. Gibson