Asymmetric Screen-film System Research Articles

非対称増感紙-フィルムシステムの物理的画質と視覚的画質の関係

非対称増感紙-フィルムシステムの物理的画質と視覚的画質の関係

Evaluation of Radiographic Mottle of Asymmetric Screen-Film System Using Psychophysical Analysis

Evaluation of Radiographic Mottle of Asymmetric Screen-Film System Using Psychophysical Analysis

Comparison of an asymmetric screen-film combination with a conventional screen-film combination for chest radiography in 51 patients.

Comparison is made between a new asymmetric screen-film combination and a conventional screen-film combination for use in chest radiography. Seven anatomical features were assessed by three consultant radiologists in each of 51 film pairs. A preference was indicated if one system better demonstrated a particular feature. Alternatively, no preference was indicated if the feature was equally demonstrated by both systems or not demonstrated at all. Any pathology incidentally noted which remained unchanged between the two films was localized to lung, mediastinum or bone and marked in the same way. The asymmetric high contrast system scored higher than the conventional system for demonstration of anatomy in both mediastinum and lungs, but no difference emerged between the two systems in the demonstration of pathology. The asymmetric screen-film system showed improved mediastinal and, to a lesser degree, improved lung detail. Further assessment in necessary to define any associated improvement in diagnostic yield.

447 胸部X線写真用に開発された非対称な増感紙/フイルムシステムの評価

447 胸部X線写真用に開発された非対称な増感紙/フイルムシステムの評価

Evaluation of an asymmetric screen‐film system for chest radiography

To evaluate the potential utility of an asymmetric screen-film system for chest radiography, its image quality and detail visibility compared with a conventional screen-film system are investigated. The basic imaging properties were evaluated by measuring Hurter and Driffield curves, resolution properties, and noise Wiener spectra. The visibility of simulated anatomical and pathological details in radiographs of a chest phantom and normal anatomy in chest radiographs of patients were evaluated subjectively. The dynamic range of each system is comparable, though the asymmetric screen-film system can provide an advantage over the conventional system due to a relative dose reduction of approximately 35% and higher resolution properties at high optical densities. The noise level of the asymmetric screen-film system is slightly greater at low optical densities and much greater at high optical densities. However, the visibility of lung details with the asymmetric screen-film system is slightly superior to the conventional screen-film system despite the increase in noise. Mediastinal and retrodiaphragmatic details are similar, though marginally superior with the asymmetric screen-film system. It is concluded that the asymmetric screen-film system provided slightly superior image quality to the conventional screen-film system for chest radiography, provided the average lung density is maintained at a higher level than is customary with conventional systems.

Objective performance characteristics of a new asymmetric screen-film system.

A study of the objective imaging characteristics of a new asymmetric screen-film system is presented herein. The system is characterized by high x-ray absorption asymmetric screens, and a low-noise, high-contrast asymmetric film having near-zero crossover. Comparisons are made with the imaging characteristics of two widely used conventional screen-film systems. Sensitometry, modulation transfer function, and noise power spectra were measured using standard methods. Granularity, noise equivalent quanta, and detective quantum efficiency were computed from these. The new screen-film system has an average gradient at lung-field densities between the two conventional systems studied, while the mediastinum contrast exceeds both conventional systems. The lung-field modulation transfer function half bandwidth of the new asymmetric system exceeds that of both conventional systems by 60%. At mid exposures the detective quantum efficiency of the new asymmetric system is comparable to those of the conventional systems studied. However, the exposure range over which detective quantum efficiency remains high is substantially wider.

非対称性増感紙・フィルム系の画像評価の理論的考察

A theoritical investigation of the image quality evaluation of asymmetric screen-film systems is developed. In connecting with the front and back side image of a film, it is helpful to assess the image quality by keeping in mind that an asymmetric screen-film system involves radiographic density rather than optical illuminance. Therefore, overall MTF depends on radiographic density comprising parallel linkage of each side MTF with relative gradient weight of an asymmetric screen-film system. Slit and chart measurement methods of MTF for asymmetric system are discussed. Consequently, it can successfully be to evaluate the image quality of the simulated asymmetric system by NEQ (u).

400. 非相称感材システムの階調特性の検討(画像工学 非対称システム)

400. 非相称感材システムの階調特性の検討(画像工学 非対称システム)

399. 非相称感材システムの有効利用の一考察 : 被写体吸収値差の対応(画像工学 非対称システム)

399. 非相称感材システムの有効利用の一考察 : 被写体吸収値差の対応(画像工学 非対称システム)

61. 非対称増感紙-フィルム系の視覚評価の定量化(画像-視覚評価法)

61. 非対称増感紙-フィルム系の視覚評価の定量化(画像-視覚評価法)

174. 胸部撮影における非対称増感紙-フィルム系の画像特性と臨床応用(第 49 回総会学術大会一般研究発表予稿)

174. 胸部撮影における非対称増感紙-フィルム系の画像特性と臨床応用(第 49 回総会学術大会一般研究発表予稿)

174. 胸部撮影における非対称増感紙 : フィルム系の画像特性と臨床応用(画像工学-4 非対称系画質評価 (2))

174. 胸部撮影における非対称増感紙 : フィルム系の画像特性と臨床応用(画像工学-4 非対称系画質評価 (2))

181. 非対称な増感紙・フィルム系の MTF 測定の検討第 3 報(第 21 回秋季学術大会一般研究発表予稿)

181. 非対称な増感紙・フィルム系の MTF 測定の検討第 3 報(第 21 回秋季学術大会一般研究発表予稿)

396. 非対称増感紙-フィルム系の MTF 測定法の比較(第 49 回総会学術大会一般研究発表予稿)

396. 非対称増感紙-フィルム系の MTF 測定法の比較(第 49 回総会学術大会一般研究発表予稿)

396. 非対称増感紙/フィルム系の MTF 測定法の検討(画像工学-7 MTF 測定法)

396. 非対称増感紙/フィルム系の MTF 測定法の検討(画像工学-7 MTF 測定法)

61. 非対称増感紙-フィルム系の視覚評価の定量化(第 21 回秋季学術大会一般研究発表予稿)

61. 非対称増感紙-フィルム系の視覚評価の定量化(第 21 回秋季学術大会一般研究発表予稿)

67. 非相称感材システムを用いた胸部写真の検討 (その 2)(第 48 回総会学術大会一般研究発表予稿)

67. 非相称感材システムを用いた胸部写真の検討 (その 2)(第 48 回総会学術大会一般研究発表予稿)

63. 非相称感材システムを用いた胸部写真の検討 (その 1)(画像技術-1 非相称感材 (1))

63. 非相称感材システムを用いた胸部写真の検討 (その 1)(画像技術-1 非相称感材 (1))

63. 非相称感材システムを用いた胸部写真の検討 (その 1)(第 48 回総会学術大会一般研究発表予稿)

63. 非相称感材システムを用いた胸部写真の検討 (その 1)(第 48 回総会学術大会一般研究発表予稿)

67. 非相称感材システムを用いた胸部写真の検討(画像技術-2 非相称感材 (2))

67. 非相称感材システムを用いた胸部写真の検討(画像技術-2 非相称感材 (2))