AIM

To investigate the advantage of digital tomosynthesis (DTS) over chest radiography (CXR) and dual-energy subtraction radiography (DES) for pulmonary nodule detection according to the location and size of solid simulated pulmonary nodules (SPNs).

MATERIALS AND METHODS

Ninety-six SPNs of variable sizes were inserted into eight different regions of a lung phantom. These regions were further classified into two groups of danger and non-danger zones based on anatomical location influencing the detection of pulmonary nodules. The 96 cases with inserted SPNs and an additional nodule-free 96 control cases all underwent CXR, DES, and DTS examinations. Three observers independently reviewed all the images. The jackknife alternative free-response receiver operating characteristic was used to analyse diagnostic performance for each technique.

RESULTS

DTS was superior to CXR and DES for detection of smaller SPNs, except in the retrodiaphragmatic and apical regions. DTS outperformed CXR and DES for detection of larger SPNs in the paramediastinal region. For 5- and 8-mm SPNs, DTS was superior to CXR and DES in the apical, paramediastinal and lateral pulmonary regions. In the retrodiaphragmatic region, the three techniques showed similar diagnostic performance regardless of the SPN size. DES was similar to DTS for detection of 8-mm SPN in the apical region. For 10- and 12-mm SPNs, CXR and DES showed similar diagnostic performance to DTS in the apical and lateral pulmonary regions; however, DTS was superior to CXR and DES in the paramediastinal region.

CONCLUSIONS

DTS significantly improved the capability to detect synthetic pulmonary nodules compared with CXR and DES, for detection of smaller nodules in the apical, paramediastinal, and lateral pulmonary regions, and larger nodules located in the paramediastinal region in a thoracic phantom.