Incidental findings from lung CT scans: implications for research

J Med Imaging Radiat Oncol. 2011 Feb;55(1):20-5. doi: 10.1111/j.1754-9485.2010.02224.x.


Introduction: We aimed to evaluate the number and nature of incidental findings in CT chest scans in the context of a study of the pulmonary effects of cannabis.

Methods: Three hundred fifty-seven participants were recruited: 78 cannabis-only smokers, 92 tobacco-only smokers, 106 smokers of cannabis and tobacco and 81 never smokers. All participants underwent a high-resolution CT scan of their thorax. Two radiologists read the scans. Associations between abnormalities and age, sex, tobacco and cannabis smoking status were expressed as odds ratios (OR) with 95% confidence interval.

Results: Seventy-six findings requiring referral or further investigations were found in 71/357 (19.9%) of participants. In multivariate analyses, only older age, OR (per decade) 2.1 (1.4 to 3.0), was associated with a respiratory abnormality on the CT scan. A total of 37/76 (48.7%) of the abnormalities detected were extra-pulmonary, with findings observed across a wide range of organ systems. Only older age, OR (per decade) 1.7 (1.2 to 2.5), was associated with a non-respiratory abnormality.

Conclusion: The common occurrence of abnormal findings requiring referral or further investigations raises practical, ethical and medico-legal issues which need to be carefully considered in research programmes utilising chest CT scanning.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Comorbidity
  • Female
  • Humans
  • Incidence
  • Incidental Findings
  • Lung / diagnostic imaging*
  • Lung Diseases / diagnostic imaging*
  • Lung Diseases / epidemiology*
  • Male
  • Middle Aged
  • New Zealand / epidemiology
  • Prevalence
  • Radiography, Thoracic / statistics & numerical data*
  • Reproducibility of Results
  • Respiration Disorders / diagnostic imaging*
  • Respiration Disorders / epidemiology*
  • Sensitivity and Specificity
  • Tomography, X-Ray Computed / statistics & numerical data*