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

K Martini; B K Barth; T D L Nguyen-Kim; S Baumueller; H Alkadhi; T Frauenfelder

doi:10.1016/j.ejrad.2015.11.036

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

Eur J Radiol. 2016 Feb;85(2):360-5. doi: 10.1016/j.ejrad.2015.11.036. Epub 2015 Dec 3.

Authors

K Martini¹, B K Barth², T D L Nguyen-Kim³, S Baumueller⁴, H Alkadhi⁵, T Frauenfelder⁶

Affiliations

¹ Institute of Diagnostic and Interventional Radiology, University Hospital Zurich/University Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland. Electronic address: katharina.martini@usz.ch.
² Institute of Diagnostic and Interventional Radiology, University Hospital Zurich/University Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland. Electronic address: borna.barth@usz.ch.
³ Institute of Diagnostic and Interventional Radiology, University Hospital Zurich/University Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland. Electronic address: thidanlinh.nguyen@usz.ch.
⁴ Institute of Diagnostic and Interventional Radiology, University Hospital Zurich/University Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland. Electronic address: Stephan.baumueller@usz.ch.
⁵ Institute of Diagnostic and Interventional Radiology, University Hospital Zurich/University Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland. Electronic address: hatem.alkadhi@usz.ch.
⁶ Institute of Diagnostic and Interventional Radiology, University Hospital Zurich/University Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland. Electronic address: thomas.frauenfelder@usz.ch.

PMID: 26781141
DOI: 10.1016/j.ejrad.2015.11.036

Abstract

Purpose: 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.

Material and 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.

Conclusion: 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.

Keywords: Computed tomography; Iterative reconstruction; Lung infection; Redused dose protocol; Tin filtration.

MeSH terms

Female
Humans
Male
Middle Aged
Multiple Pulmonary Nodules / diagnostic imaging*
Prospective Studies
Radiation Dosage*
Radiographic Image Interpretation, Computer-Assisted / methods
Radiography, Thoracic / methods*
Sensitivity and Specificity
Tomography, X-Ray Computed / methods*