DIGITAL CHEST RADIOGRAPHY WITH A LARGE IMAGE INTENSIFIER Evaluation of diagnostic performance and patient exposure, L. G. MANSSON et al., Acta Radiologica, 30(4), 337〜342, (1989)

Large-screen image intensifier (II) photofluorography was compared with full-size screen-film chest radiography in the diagnosis of pulmonary emphysema in 84 patients. Photospot films and conventional radiographs were interpreted independently by three radiologists. Computed tomography (CT) was used as an independent reference technique, and diagnostic performance of chest radiography in various CT patterns of emphysema was evaluated. The difference in diagnostic sensitivity for emphysema in favor of conventional chest radiography over photofluorography (0.65 versus 0.56) was statistically significant (p<0.05). Specificity of the imaging modalities was equal: 0.78 in full-size films and 0.77 in photospot films. All CT patterns of emphysema had great false negative response rates in chest radiography, which is an inaccurate technique for the diagnosis of emphysema. CT is required for reliable radiologic evaluation of emphysema.

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Image Intensifier Based Digital Chest Radiography

Acta Radiologica ◽

10.1177/028418519303400617 ◽

1993 ◽

Vol 34 (6) ◽

pp. 618-621

Author(s):

S. Kheddache ◽

L. Denbratt ◽

J. E. Angelhed ◽

D. Schlossman

Keyword(s):

Chest Radiography ◽

Digital Images ◽

Clinical Importance ◽

Image Intensifier ◽

Contrast Resolution ◽

Fine Line ◽

Visual Grading Analysis ◽

Digital Chest ◽

Digital Monitor

Contrast- and edge-enhanced digital monitor images from an image intensifier system for chest radiography were compared to conventional radiograms using visual grading analysis. Eleven observers graded the visibility of rounded opacities, the carinal region, fine line structures, and also compared the overall quality of images from 20 patients. The results showed significantly better visibility on the digital monitor for the rounded opacities and the mediastinum compared to the conventional radiograms. The overall quality of the digital images was also considered better. However, the digital images showed significantly inferior visibility for the line structures in comparison with the conventional radiograms. Our study indicates that the present contrast- and edge-enhanced digital images, with a spatial resolution of 1 024 × 1024 pixels and a contrast resolution of 8 bits, are superior to conventional radiograms for the visualization of mediastinal anatomy and rounded opacities. The clinical importance of the inferior visibility of fine line structures is not clear.

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Digital Chest Radiography with a Large Image Intensifier

Acta Radiologica ◽

10.1177/028418518903000401 ◽

1989 ◽

Vol 30 (4) ◽

pp. 337-342 ◽

Cited By ~ 4

Author(s):

L. G. Månsson ◽

S. Kheddache ◽

D. Schlossman ◽

J. Börjesson ◽

E. Håkansson ◽

...

Keyword(s):

Spatial Resolution ◽

Chest Radiography ◽

Image Intensifier ◽

Conventional Technique ◽

Low Contrast ◽

Conventional Film ◽

Digital Chest ◽

Froc Analysis ◽

Screen System ◽

Digital Monitor

A digital system for chest radiography based on a large image intensifier was compared with a conventional film-screen system. The diagnostic performance was evaluated with special reference to the digital monitor images with a modified version of receiver operating characteristic (ROC) analysis—free response ROC (FROC) analysis—on a chest equivalent phantom. Measurements of spatial resolution and energy imparted were also performed. The detectability of low-contrast objects as well as spatial resolution was better for the full-size film-screen radiographs than for both the digital monitor images and the 100 mm photofluorograms. The image-intensifier system has a potential for considerable dose savings in relation to the conventional technique provided that fluoroscopy is excluded in the positioning of the patients.

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