title: Evaluation of pulmonary nodules and infection on chest CT with radiation dose equivalent to chest radiography: Prospective intra-individual comparison study to standard dose CT.
abstract: OBJECTIVE
  To compare prospectively, in patients undergoing chest computed tomography (CT) for pulmonary-nodules or infection, image-quality and accuracy of standard dose (SD) and reduced dose (RD) CT with tin-filtration.
  
  
  METHODS
  This IRB-approved study included 100 consecutive patients (36 female;median age 56 years) referred for follow-up of pulmonary-nodules (n=43) or suspicion of infection (n=57) undergoing single-energy CT with SD and RD using tin-filtration at 100 kVp (CTDIvol 2.47 mGy and 0.07 mGy, respectively). Images were reconstructed with advanced modeled iterative reconstruction (ADMIRE) at strength 3 and 5. Image-noise was measured. Two independent readers evaluated nodules and pulmonary-infection. SD CT served as reference standard.
  
  
  RESULTS
  No significant difference was found in noise between RD with ADMIRE5 and SD with ADMIRE3 (118HU ± 14 vs. 120HU ± 17; p=0.08). Sensitivity for detection of atelectasis and interstitial lung changes was higher in images reconstructed with ADMIRE5 (93% and 88%; respectively) than in those reconstructed with ADIMRE3 (77% and 78%; respectively). Sensitivity for detection of consolidations was 90% for ADMIRE3 and 89% for ADMIRE5. Sensitivity for nodule detection was 71% for ADMIRE3 and 81% for ADMIRE5. Specificity for detection of atelectasis and interstitial lung changes was 99% and 96% with ADMIRE5 and 99% and 96% with ADMIRE3. Specificity for detection of consolidations was 99% for ADMIRE3 and 5. Specificity for detection of nodules was 87% for both ADMIRE3 and 5.
  
  
  CONCLUSIONS
  Chest CT with a radiation dose equivalent to conventional radiography is feasible and allows for detection of pulmonary infection with high sensitivity, whereas the accuracy for detecting nodules is only moderate.
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich/University Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland. Electronic address: katharina.martini@usz.ch.
authors.forename: K
authors.initials: K
authors.lastname: Martini
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich/University Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland. Electronic address: borna.barth@usz.ch.
authors.forename: B K
authors.initials: BK
authors.lastname: Barth
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich/University Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland. Electronic address: thidanlinh.nguyen@usz.ch.
authors.forename: T D L
authors.initials: TD
authors.lastname: Nguyen-Kim
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich/University Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland. Electronic address: Stephan.baumueller@usz.ch.
authors.forename: S
authors.initials: S
authors.lastname: Baumueller
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich/University Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland. Electronic address: hatem.alkadhi@usz.ch.
authors.forename: H
authors.initials: H
authors.lastname: Alkadhi
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich/University Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland. Electronic address: thomas.frauenfelder@usz.ch.
authors.forename: T
authors.initials: T
authors.lastname: Frauenfelder
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055613:Multiple Pulmonary Nodules / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D013902:Radiography, Thoracic / Q000379:methods*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Computed tomography; Iterative reconstruction; Lung infection; Redused dose protocol; Tin filtration