Inclusion Criteria:  Age 18-80 years At least 1 IPN identified on CT imaging measuring 4-30 mm in maximal diameter CT slice thickness of 3 mm or less  Exclusion Criteria:  Previous diagnosis of lung cancer History of haemoptysis Unexplained weight loss > 7 kg in the preceding 12 months Past history of malignancy within 5 years (excluding non-melanoma skin cancer)