title: Role of digital tomosynthesis and dual energy subtraction digital radiography in detecting pulmonary nodules.
abstract: OBJECTIVE
  Digital tomosynthesis (DT) and dual-energy subtraction digital radiography (DES-DR) are known to perform better than conventional radiography in the detection of pulmonary nodules. Yet the comparative diagnostic performances of DT, DES-DR and digital radiography (DR) is not known. The present study compares the diagnostic performances of DT, DES-DR and DR in detecting pulmonary nodules.
  
  
  METHODS
  The institutional Review Board approved the study and informed written consent was obtained. Fifty-five patients (30 with pulmonary nodules, 25 with non-nodular focal chest pathology) were included in the study. DT and DES-DR were performed within 14 days of MDCT. Composite images acquired at high kVp as part of DES-DR were used as DR images. Images were analyzed for presence of nodules and calcification in nodules. Interpretations were assigned confidence levels from 1 to 5 according to Five-Point rating scale. Areas under the receiver operating characteristic curves were compared using Z test.
  
  
  RESULTS
  A total of 110 (88 non-calcified, 22 calcified) nodules were identified on MDCT. For detection of nodules, DR showed cumulative sensitivity and specificity of 25.45% and 67.97%, respectively. DT showed a cumulative sensitivity and specificity of 60.9% and 85.07%, respectively. The performance was significantly better than DR (p<0.003). DES-DR showed sensitivity and specificity of 27.75% and 82.64%, not statistically different from those of DR (p-0.92). In detection of calcification, there was no statistically significant difference between DT, DES-DR and DR.
  
  
  CONCLUSIONS
  DT performs significantly better than DES-DR and DR at the cost of moderate increase in radiation dose.
authors.affiliation: Department of Radiodiagnosis and Imaging, Postgraduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh 160012, India.
authors.forename: Sarvana G
authors.initials: SG
authors.lastname: Kumar
authors.affiliation: Department of Radiodiagnosis and Imaging, Postgraduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh 160012, India. Electronic address: gargmandeep01@gmail.com.
authors.forename: Mandeep Kumar
authors.initials: MK
authors.lastname: Garg
authors.affiliation: Department of Radiodiagnosis and Imaging, Postgraduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh 160012, India.
authors.forename: Niranjan
authors.initials: N
authors.lastname: Khandelwal
authors.affiliation: Department of Radiodiagnosis and Imaging, Postgraduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh 160012, India.
authors.forename: Pankaj
authors.initials: P
authors.lastname: Gupta
authors.affiliation: Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh 160012, India.
authors.forename: Dheeraj
authors.initials: D
authors.lastname: Gupta
authors.affiliation: Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh 160012, India.
authors.forename: Ashutosh Nath
authors.initials: AN
authors.lastname: Aggarwal
authors.affiliation: Department of Radiodiagnosis and Imaging, Postgraduate Institute of Medical Education and Research (PGIMER), Sector 12, Chandigarh 160012, India.
authors.forename: Subash Chand
authors.initials: SC
authors.lastname: Bansal
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D055613:Multiple Pulmonary Nodules / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D012372:ROC Curve; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D013902:Radiography, Thoracic / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*; D055815:Young Adult
keywords: Digital radiography; Digital tomosynthesis; Dual energy subtraction radiography; Pulmonary nodule