Effects of optimization and image processing in digital chest radiography: an ROC study with an anthropomorphic phantom
Autor: | L. Denbratt, D. Schlossman, B Gottfridsson, Susanne Kheddache, Jan-Erik Angelhed, Lars Gunnar Månsson |
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Rok vydání: | 1991 |
Předmět: |
Lung Diseases
Time Factors Image quality Radiography Image processing law.invention Digital image law Digital image processing Image Processing Computer-Assisted Medicine Humans Radiology Nuclear Medicine and imaging Observer Variation business.industry Contrast resolution Image intensifier Pneumothorax General Medicine Edge enhancement respiratory system respiratory tract diseases Models Structural Radiographic Image Enhancement ROC Curve Evaluation Studies as Topic Radiography Thoracic business Nuclear medicine |
Zdroj: | European journal of radiology. 13(2) |
ISSN: | 0720-048X |
Popis: | A digital system for chest radiography based on a large image intensifier was compared to a conventional film-screen system. The digital system was optimized with regard to spatial and contrast resolution and dose. The images were digitally processed for contrast and edge enhancement. A simulated pneumothorax and two simulated nodules were positioned over the lungs and the mediastinum of an anthropomorphic phantom. Observer performance was evaluated with ROC analysis. Five observers assessed the processed digital images and the conventional full-size radiographs. The time spent viewing the full-size radiographs and the digital images was recorded. For the simulated pneumothorax, the results showed perfect performance for the full-size radiographs and detectability was high also for the processed digital images. No significant difference in the detectability of the simulated nodules was seen between the two imaging systems. The results for the digital images showed a significantly improved detectability for the nodules in the mediastinum as compared to a previous ROC study where no optimization and image processing was available. No significant difference in detectability was seen between the former and the present ROC study for small nodules in the lung. No difference was seen in the time spent assessing the conventional full-size radiographs and the digital images. The study indicates that processed digital images produced by a large image intensifier are equal in image quality to conventional full-size radiographs for low-contrast objects such as nodules. |
Databáze: | OpenAIRE |
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