Radiografía digital de tórax: efecto del filtrado espacial y de la visualización mediante monitor en el diagnóstico de neumotórax

Objective: To study the validity of digital chest images in the diagnosis of pneumothorax, the results obtained with plain radiography were compared with the images visualized on cathode ray tube (video) monitors with a resolution of 2,430 x 2,000 pixels. Plain radiography was also compared with digital radiography processed using either a global filter and by means of adaptive filtration, two methods that involve film-screen systems. Material and methods: A series of 113 PA chest radiographs was studied, including 47 cases of pneumothorax, 44 normal images and 22 cases involving other diseases. The images were visualized by four radiologists whose observations were used to calculate the sensitivity and specificity, receiver operating characteristic (ROC) curves and the areas under the curves for each radiologist and imaging technique. Results: The comparison of the areas under the ROC curves disclosed no significant differences between any of the techniques studied. Conclusions: Our results indicate that the visualization of the images using a video monitor at a resolution of 2,430 x 2,000 pixels may be a valid alternative to plain radiographs for the detection of pneumothorax. Spatial filtration for high-frequency enhancement, whether global or adaptive, does not improve the results of plain radiography or film-screen visualization.