Measurement of Rounded Opacities in the Lung of X-Ray Images towards Quantitative Diagnosis of Pneumoconiosis.
Toriwaki-J; Chan-X; Hasegawa-J
NIOSH 1990 Nov:1358-1363
A new method for automated classification of pneumoconiosis chest X- ray films was presented in which individual small rounded opacities are recognized and classified by their measured density. It was demonstrated by experiments using International Labour Organization standard pneumoconiosis films and the computed radiography images that the opacity density measured by the proposed procedure was approximately proportional to the categories of profusion of pneumoconiosis. To improve the system performance, it was necessary to develop a procedure to recognize blood vessel shadows more correctly. The individual opacities detected by this system were compared with those by experienced radiologists to evaluate accuracy in opacity recognition. From the results, not only the density values will be available as one of the effective features for computer diagnosis of pneumoconiosis, but also the detected small rounded opacities may be provided to the readers as reference data which would be useful in training readers of pneumoconiosis films. In the new process the small rounded opacities in an input image were enhanced by a linear filter with a weight function design based on a model of the small rounded opacity, then candidates of the opacities were obtained as a connected component pattern by thresholding the filtered image. The components due to shadows of ribs and vessels were removed by using a shape feature of a connected component to detect only objects suspected to be caused by the small rounded opacities. The film was categorized according to the opacity density which is given by the ratio of the area or the number of the extracted opacities to the area of the lung region.
Respiratory-system-disorders; Lung-disease; Diagnostic-techniques; X-ray-diagnosis; Radiodiagnosis; X-ray-analysis; Pulmonary-system;
DHHS (NIOSH) Publication No. 90-108
Asthma and Chronic Obstructive Pulmonary Disease; Disease and Injury; Respiratory-system-disorders; Pulmonary-system;
Proceedings of the VIIth International Pneumoconioses Conference