Visual assessment of calcification in solitary pulmonary nodules on chest radiography: correlation with volumetric quantification of calcification
- 14 Downloads
To assess the ability of digital chest radiography (CXR) to reveal calcification in solitary pulmonary nodules (SPNs), and to examine the correlation between a visual assessment and volumetric quantification of the calcification.
Materials and methods
This study was a retrospective review of 220 SPNs identified by both CXR and chest CT. Eleven observers did blind review of the CXR images and scored nodule calcification on a confidence scale of 1 to 5. The area under the receiver operating characteristics (ROC) curve (AUC) was obtained to analyze the diagnostic performance. The intraclass correlation coefficient (ICC) for interrater reliability was calculated. The AUC and ICC were calculated according to the following nodule diameter groups: group 1 (< 10 mm), group 2 (≥ 10 mm and < 20 mm), and group 3 (≥ 20 mm).
Of the 220 SPNs, 145 SPNs (65.6%) were identified as non-calcified and 75 (34.4%) as calcified. The average percentage of calcification volume in SPN > 160 HU (Vol160HU) among the 75 calcified nodules was 47.5%. The mean Vol160HU of the 68 SPNs classified as having definite calcification was 51.1%. The overall AUC was 0.71. The AUCs for groups 1, 2, and 3 was 0.835, 0.639, and 0.620, respectively. The ICCs for groups 1, 2, 3 was 0.65, 0.48, and 0.33, respectively.
The overall diagnostic performance of digital CXR to predict calcification in SPNs was moderately accurate and the diagnostic performance for predicting calcification in SPNs was significantly higher, and interobserver reproducibility was good when SPN < 10 mm compared with ≥ 10 mm in diameter.
• The misdiagnosis of a non-calcified nodule as a calcified one by CXR could lead to poor management choices for the SPN.
• The diagnostic performance of CXR in predicting calcification was best for nodules < 10 mm in diameter. SPNs with calcification of approximately 50% of their volume tend to be considered calcified.
• The diagnostic performance of CXR in identifying calcification was low for nodules ≥ 10 mm in diameter; therefore, we should carefully evaluate calcification carefully for nodules ≥ 10 mm.
KeywordsSolitary pulmonary nodule Radiography, thoracic Tomography, X-ray computed
Automatic exposure control
Area under the ROC curve
Intraclass correlation coefficient
Negative predictive value
Positive predictive value
Receiver operating characteristic
Solitary pulmonary nodules
This research was supported by the MSIT (Ministry of Science and ICT), Korea, under the ITRC (Information Technology Research Center) support program (IITP-2018-2016-0-00309) supervised by the IITP (Institute for Information and Communications Technology Promotion).
Compliance with ethical standards
The scientific guarantor of this publication is Joo Sung Sun.
Conflict of interest
The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article.
Statistics and biometry
No complex statistical methods were necessary for this paper.
Written informed consent was waived by the Institutional Review Board.
Institutional Review Board approval was obtained.
• Performed at one institution
- 1.Tan BB, Flaherty KR, Kazerooni EA, Iannettoni MD, American College of Chest Physicians (2003) The solitary pulmonary nodule. Chest 123:89S–96SGoogle Scholar
- 25.Jain DG (2012) Cancer in the solitary pulmonary nodule. Journal, Indian Academy of Clinical Medicine JIACM 13(2):116–126Google Scholar