Effects of dual-energy subtraction chest radiography on detection of small pulmonary nodules with varying attenuation: receiver operating characteristic analysis using a phantom study

• Published in: Japanese Journal of Radiology Vol. 28; no. 3; pp. 214 - 219
• Main Authors: Oda, Seitaro, Awai, Kazuo, Funama, Yoshinori, Utsunomiya, Daisuke, Yanaga, Yumi, Kawanaka, Koichi, Yamashita, Yasuyuki
• Format: Journal Article
• Language: English
• Published: Japan Springer Japan 01.04.2010; Springer Nature B.V
• Subjects: Humans; Imaging; Lung - diagnostic imaging; Lung Neoplasms - diagnostic imaging; Medicine; Medicine & Public Health; Nuclear Medicine; Original Article; Phantoms, Imaging; Predictive Value of Tests; Radiography, Dual-Energy Scanned Projection; Radiography, Thoracic; Radiology; Radiotherapy; ROC Curve; Sensitivity and Specificity; Solitary Pulmonary Nodule - diagnostic imaging; Subtraction Technique; Phantom; Flat-panel detector; Chest radiography; ROC analysis; Dual-energy subtraction
• ISSN: 1867-1071; 1867-108X; 1862-5274; 1867-108X
• DOI: 10.1007/s11604-009-0411-7

Purpose The aim of this study was to investigate the detectability of simulated pulmonary nodules with different X-ray attenuation by flat-panel detector (FPD) chest radiography using a dual-exposure dual-energy subtraction (DES) technique. Materials and methods Using a FPD radiography system, we obtained 108 sets of chest radiographs of a chest phantom. They consisted of 54 sets each of chest radiographs with and without simulated nodules. Each data set contained a standard and a corresponding dualenergy subtracted chest radiograph (DES image). The diameters of the simulated nodules were 8, 10, and 12 mm, respectively; nodules of each size manifested attenuation of −450, −200, and 30 Hounsfield units (HU). We performed receiver operating characteristic (ROC) analysis to compare the observers’ performance in detecting nodules. Results For the −450 HU nodules the mean areas under the ROC curve (AUC) without and with DES images were 0.66 and 0.77, respectively; the difference was significant (paired t -test, P < 0.01). For nodules with −200 and 30 HU, there was no significant difference in the AUC value (0.79 vs. 0.77, P = 0.13; 0.92 vs. 0.94, P = 0.17, respectively). Conclusion The addition of DES images to standard chest radiographs improved the performance of radiologists charged with detecting simulated nodules with an attenuation of −450 HU.