BACKGROUND: Incidental findings of suspect lung opacities are common in computed tomography (CT)-based thorax examinations, especially in high-risk patients, such as stroke patients. Screening with CT of the thorax has detected lung cancer in approximately .31%-1.20% of high-risk populations. The aim of the present study was to report the frequency of suspect lung opacities on routine acute stroke imaging.

METHODS: Seven hundred and fifty-seven consecutive stroke patients evaluated for intravenous thrombolysis treatment within 4.5 hours of symptom debut, from June 2009 to December 2011, were included in a prospective registry on which this analysis was based. On admission, CT angiography from the aortic arch to vertex was performed, including the lung apices, corresponding to 1/3 of the total lung volume. A senior neuroradiologist reviewed all scans registering suspect lung opacities, which subsequently were characterized as either malignant, presumed malignant, presumed benign or benign, based on radiologic parameters of malignancy, positron emission tomography scan, histology, and clinical features.

RESULTS: Suspect lung opacities appeared on the CT angiography in 20 patients (2.6%). Five suspect lung opacities were categorized as malignant and 3 suspect lung opacities were categorized as presumed malignant. This corresponds to an incidence of 1.1% (8 of 750).

CONCLUSIONS: Malignant lung opacities were found in approximately 1% of this high-risk population, whereas our findings do not support full CT of the thorax as routine on stroke patients.