記述言語：英語   出版者・発行元：Physical and Engineering Sciences in Medicine  

Chest x-ray imaging is widely used for the diagnosis of chest diseases but has low sensitivity for detecting pulmonary nodules due to anatomical overlaps. Dual-energy subtraction (DES) imaging can improve nodule visibility by reducing bone obscuration. This study aims to evaluate the image quality of a new one-shot DES (OSDES) system with a dual-layer flat-panel detector compared with the widely used two-shot DES (TSDES) system. Chest phantom images of various simulated nodules (8,10, and 12 mm) were acquired using both DES systems at several exposure doses, lung regions, and two types of body sizes (standard and large). Independent observers evaluated the visibility of the nodules under each condition using visual grading analysis scores (VGASs). The VGASs of OSDES images were significantly higher than those of TSDES images across all nodule sizes, lung regions, exposure doses, and body sizes, except for the standard chest phantom with a 10-mm nodule and without ribs. In particular, the VGAS of an 8-mm nodule in the region with one overlapping rib of the standard sized phantom was 2.46 with OSDES and 1.03 with TSDES, with the visibility of the nodule being significantly improved with the OSDES system. Thus, the OSDES system, using a dual-layer flat-panel detector and one exposure, offers superior visibility of pulmonary nodules with reduced dose compared with the TSDES system, suggesting its potential for improved clinical diagnosis without motion artifacts.

DOI： 10.1007/s13246-025-01561-x

Web of Science

Scopus

PubMed

記述言語：英語   出版者・発行元：Academic Radiology  

Rationale and Objectives: Dual-energy subtraction (DES) imaging constitutes a technique that has demonstrated efficacy in enhancing the detectability of pulmonary nodules on chest radiographs. However, a simple and quantitative methodology for evaluating the clinical image quality of DES images is currently lacking. The objective of this study was to investigate the applicability of contrast-detail (C-D) phantom analysis to the visual clinical image quality evaluation of chest DES images. Materials and Methods: We employed a custom-made phantom incorporating the C-D phantom and a multipurpose anthropomorphic adult chest phantom. Two phantom sizes were utilized to simulate standard- and large-bodied adult patients for each phantom. The custom-made phantom images were scored automatically using dedicated software, yielding an inverse image quality figure (IQF<inf>inv</inf>) value. The multipurpose anthropomorphic adult chest phantom was employed in a visual grading analysis (VGA) study that was conducted by two experienced radiologists and five radiological technologists. Each nodule placed in the chest phantom image was rated on a 4-point Likert scale. Results: A statistically significant correlation was observed between the VGA scores of the seven observers and the obtained IQF<inf>inv</inf> values. Conclusion: The findings of this study suggest that DES image analysis of the C-D phantom possesses the potential to be utilized for the evaluation of clinical DES image quality based on chest lesion detectability.

DOI： 10.1016/j.acra.2023.10.016

Web of Science

Scopus

PubMed

記述言語：英語   出版者・発行元：Radiography  

Introduction: Dual-energy subtraction (DES) imaging can obtain chest radiographs with high contrast between nodules and healthy lung tissue, and evaluating of chest radiography and evaluating exposure conditions is crucial to obtain a high-quality diagnostic image. This study aimed to investigate the effect of the dose allocation ratio of entrance surface dose (ESD) between high- and low-energy projection in low-contrast resolution of soft-tissue images for two-shot DES imaging in digital radiography using a contrast-detail phantom (CD phantom). Methods: A custom-made phantom mimicking a human chest that combined a CD phantom, polymethylmethacrylate square plate, and an aluminum plate (1–3 mm) was used. The tube voltage was 120 kVp (high-energy) and 60 kVp (low-energy). The ESD was changed from 0.1 to 0.5 mGy in 0.1 mGy increments. Dose allocation ratio of ESD between 120 kVp and 60 kVp projection was set at 1:1, 1:2, 1:3, and 2:1. Inverse image quality figure (IQF<inf>inv</inf>) was calculated from the custom-made phantom images. Results: When the total ESD and aluminum thickness were constant, no significant difference in IQF<inf>inv</inf> was observed under most conditions of varied dose allocation ratio. Similarly, when the total ESD and the dose allocation ratio were constant, there was no significant difference in IQF<inf>inv</inf> based on the aluminum plate thickness. Conclusion: Using IQF<inf>inv</inf> to evaluate the quality of the two-shot DES image suggested that dose allocation ratio did not have a significant effect on low-contrast resolution of soft-tissue images. Implications for practice: The present results provide useful information for determining exposure conditions for two-shot DES imaging.

DOI： 10.1016/j.radi.2022.11.007

Scopus

PubMed