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1.  Development of Standard Digital Images for Pneumoconiosis 
Journal of Korean Medical Science  2011;26(11):1403-1408.
We developed the standard digital images (SDIs) to be used in the classification and recognition of pneumoconiosis. From July 3, 2006 through August 31, 2007, 531 retired male workers exposed to inorganic dust were examined by digital (DR) and analog radiography (AR) on the same day, after being approved by our institutional review board and obtaining informed consent from all participants. All images were twice classified according to the International Labour Office (ILO) 2000 guidelines with reference to ILO standard analog radiographs (SARs) by four chest radiologists. After consensus reading on 349 digital images matched with the first selected analog images, 120 digital images were selected as the SDIs that considered the distribution of pneumoconiosis findings. Images with profusion category 0/1, 1, 2, and 3 were 12, 50, 40, and 15, respectively, and a large opacity were in 43 images (A = 20, B = 22, C = 1). Among pleural abnormality, costophrenic angle obliteration, pleural plaque and thickening were in 11 (9.2%), 31 (25.8%), and 9 (7.5%) images, respectively. Twenty-one of 29 symbols were present except cp, ef, ho, id, me, pa, ra, and rp. A set of 120 SDIs had more various pneumoconiosis findings than ILO SARs that were developed from adequate methods. It can be used as digital reference images for the recognition and classification of pneumoconiosis.
PMCID: PMC3207041  PMID: 22065894
Pneumoconiosis; Digital radiography; Analog radiography; ILO classification
2.  An Automatic Computer-Aided Detection Scheme for Pneumoconiosis on Digital Chest Radiographs 
Journal of Digital Imaging  2010;24(3):382-393.
This paper presents an automatic computer-aided detection scheme on digital chest radiographs to detect pneumoconiosis. Firstly, the lung fields are segmented from a digital chest X-ray image by using the active shape model method. Then, the lung fields are subdivided into six non-overlapping regions, according to Chinese diagnosis criteria of pneumoconiosis. The multi-scale difference filter bank is applied to the chest image to enhance the details of the small opacities, and the texture features are calculated from each region of the original and the processed images, respectively. After extracting the most relevant ones from the feature sets, support vector machine classifiers are utilized to separate the samples into the normal and the abnormal sets. Finally, the final classification is performed by the chest-based report-out and the classification probability values of six regions. Experiments are conducted on randomly selected images from our chest database. Both the training and the testing sets have 300 normal and 125 pneumoconiosis cases. In the training phase, training models and weighting factors for each region are derived. We evaluate the scheme using the full feature vectors or the selected feature vectors of the testing set. The results show that the classification performances are high. Compared with the previous methods, our fully automated scheme has a higher accuracy and a more convenient interaction. The scheme is very helpful to mass screening of pneumoconiosis in clinic.
PMCID: PMC3092047  PMID: 20174852
Pneumoconiosis; digital radiography; computer-aided detection (CAD); active shape model (ASM); texture analysis; support vector machine (SVM)
3.  Computerized Analysis of Pneumoconiosis in Digital Chest Radiography: Effect of Artificial Neural Network Trained with Power Spectra 
Journal of Digital Imaging  2010;24(6):1126-1132.
It is difficult for radiologists to classify pneumoconiosis with small nodules on chest radiographs. Therefore, we have developed a computer-aided diagnosis (CAD) system based on the rule-based plus artificial neural network (ANN) method for distinction between normal and abnormal regions of interest (ROIs) selected from chest radiographs with and without pneumoconiosis. The image database consists of 11 normal and 12 abnormal chest radiographs. These abnormal cases included five silicoses, four asbestoses, and three other pneumoconioses. ROIs (matrix size, 32 × 32) were selected from normal and abnormal lungs. We obtained power spectra (PS) by Fourier transform for the frequency analysis. A rule-based method using PS values at 0.179 and 0.357 cycles per millimeter, corresponding to the spatial frequencies of nodular patterns, were employed for identification of obviously normal or obviously abnormal ROIs. Then, ANN was applied for classification of the remaining normal and abnormal ROIs, which were not classified as obviously abnormal or normal by the rule-based method. The classification performance was evaluated by the area under the receiver operating characteristic curve (Az value). The Az value was 0.972 ± 0.012 for the rule-based plus ANN method, which was larger than that of 0.961 ± 0.016 for the ANN method alone (P ≤ 0.15) and that of 0.873 for the rule-based method alone. We have developed a rule-based plus pattern recognition technique based on the ANN for classification of pneumoconiosis on chest radiography. Our CAD system based on PS would be useful to assist radiologists in the classification of pneumoconiosis.
PMCID: PMC3222544  PMID: 21153856
Computer-aided diagnosis (CAD); Pneumoconiosis; Chest radiography; Power spectra; Artificial neural network
4.  Development of CAD based on ANN analysis of power spectra for pneumoconiosis in chest radiographs: effect of three new enhancement methods 
We have been developing a computer-aided detection (CAD) scheme for pneumoconiosis based on a rule-based plus artificial neural network (ANN) analysis of power spectra. In this study, we have developed three enhancement methods for the abnormal patterns to reduce false-positive and false-negative values. The image database consisted of 2 normal and 15 abnormal chest radiographs. The International Labour Organization standard chest radiographs with pneumoconiosis were categorized as subcategory, size, and shape of pneumoconiosis. Regions of interest (ROIs) with a matrix size of 32 × 32 were selected from normal and abnormal lungs. Three new enhanced methods were obtained by window function, top-hat transformation, and gray-level co-occurrence matrix analysis. We calculated the power spectrum (PS) of all ROIs by Fourier transform. For the classification between normal and abnormal ROIs, we applied a combined analysis using the ruled-based plus the ANN method. To evaluate the overall performance of this CAD scheme, we employed ROC analysis for distinguishing between normal and abnormal ROIs. On the chest radiographs of the highest categories (severe pneumoconiosis) and the lowest categories (early pneumoconiosis), this CAD scheme achieved area under the curve (AUC) values of 0.93 ± 0.02 and 0.72 ± 0.03. The combined rule-based plus ANN method with the three new enhanced methods obtained the highest classification performance for distinguishing between abnormal and normal ROIs. Our CAD system based on the three new enhanced methods would be useful in assisting radiologists in the classification of pneumoconiosis.
PMCID: PMC4098051  PMID: 24414539
Computer-aided diagnosis (CAD); Pneumoconiosis; Chest radiography; Power spectra; Artificial neural network
6.  Epidemiological study of pneumoconiosis in the Italian poly(vinyl chloride) industry. 
Among 1216 workers employed in a poly(vinyl chloride) production factory, 20 cases of pneumoconiosis were found. None of these workers had had previous exposure to organic or inorganic dusts; 731 had been exposed to PVC dust (employed in drying, sacking and blending of polymer) and 485 had been exposed to monomer alone. Chest x-ray films were read by two independent physicians utilizing the ILO/UC Pneumoconiosis Classification, 1971. X-ray abnormalities were characterized by limited profusion, irregular type and low gravidity; in a small percentage of cases these were associated with slight restrictive respiratory function impairments. All 20 workers with PVC-induced pneumoconiosis had been exposed to high PVC dust pollution for at least five years. Mild nonspecific alterations (profusion of 0/1 class) were found both in the group exposed to PVC dust and in the group exposed to VCM alone. Such changes (observed in 388 cases, 31.9% of the whole population), are related mainly to age and smoking habits, and the role of exposure is minor.
PMCID: PMC1568843  PMID: 7333233
7.  Pneumoconiosis in animals exposed to poly(vinyl chloride) dust. 
Rats, guinea pigs and monkeys were exposed by inhalation (6 hr/day, 5 days/week) for up to 22 months to a 13 mg/m3 concentration of PVC dust. Autopsies on rats and guinea pigs were performed after 12 months of exposure and on monkeys after 22 months after 22 months of exposure. Lung function tests were performed on monkeys after 9, 14 and 22 months of exposure. Aggregates of alveolar macrophages containing PVC particles were found in the lungs of all animals. These aggregates were more numerous in the monkey lungs. No fibrosis or significant cellular infiltrates were present in or near these cellular aggregates. No significant effects on pulmonary function could be demonstrated in the monkeys exposed to PVC. Under the conditions of this experiment, inhaled PVC produced a benign pneumoconiosis.
PMCID: PMC1568841  PMID: 6800783
8.  Silicosis and coal workers' pneumoconiosis. 
Environmental Health Perspectives  2000;108(Suppl 4):675-684.
Exposure to coal mine dust and/or crystalline silica results in pneumoconiosis with initiation and progression of pulmonary fibrosis. This review presents characteristics of simple and complicated coal workers' pneumoconiosis (CWP) as well as pathologic indices of acute and chronic silicosis by summarizing results of in vitro, animal, and human investigations. These results support four basic mechanisms in the etiology of CWP and silicosis: a) direct cytotoxicity of coal dust or silica, resulting in lung cell damage, release of lipases and proteases, and eventual lung scarring; b) activation of oxidant production by pulmonary phagocytes, which overwhelms the antioxidant defenses and leads to lipid peroxidation, protein nitrosation, cell injury, and lung scarring; c) activation of mediator release from alveolar macrophages and epithelial cells, which leads to recruitment of polymorphonuclear leukocytes and macrophages, resulting in the production of proinflammatory cytokines and reactive species and in further lung injury and scarring; d) secretion of growth factors from alveolar macrophages and epithelial cells, stimulating fibroblast proliferation and eventual scarring. Results of in vitro and animal studies provide a basis for proposing these mechanisms for the initiation and progression of pneumoconiosis. Data obtained from exposed workers lend support to these mechanisms.
PMCID: PMC1637684  PMID: 10931786
9.  Reactive oxygen species: their relation to pneumoconiosis and carcinogenesis. 
Environmental Health Perspectives  1998;106(Suppl 5):1151-1155.
Occupational exposures to mineral particles cause pneumoconiosis and other diseases, including cancer. Recent studies have suggested that reactive oxygen species (ROS) may play a key role in the mechanisms of disease initiation and progression following exposure to these particles. ROS-induced primary stimuli result in the increased secretion of proinflammatory cytokines and other mediators, promoting events that appear to be important in the progression of cell injury and pulmonary disease. We have provided evidence supporting the hypothesis that inhalation of insoluble particles such as asbestos, agricultural dusts, coal, crystalline silica, and inorganic dust can be involved in facilitating multiple pathways for persistent generation of ROS, which may lead to a continuum of inflammation leading to progression of disease. This article briefly summarizes some of the recent findings from our laboratories with emphasis on the molecular events by which ROS are involved in promoting pneumoconiosis and carcinogenesis.
PMCID: PMC1533374  PMID: 9788890
11.  Haematite Pneumoconiosis in Cumberland Miners * 
Journal of Clinical Pathology  1957;10(3):187-199.
PMCID: PMC1024048  PMID: 13463104
12.  Coalminers' Pneumoconiosis 
British Medical Journal  1972;2(5809):353.
PMCID: PMC1788150
16.  "Labrador lung": an unusual mixed dust pneumoconiosis. 
Forty-eight workers involved for various periods from 1962 in mining and milling iron-containing rock in the Carol Lake area of western Labrador were found in late 1974 and early 1975 to have pneumoconiosis. Their annual chest roentgenograms demonstrated irregular nodular densities, and several revealed mild hilar lymphadenopathy or pleural thickening. All 48 workers were asymptomatic and had normal pulmonary function; their average age was 38 years. At work they had been exposed to high levels of dust containing iron, silica and anthophyllite, a type of asbestos. Lung biopsy specimens from 13 of them showed widespread focal fibrosis, large amounts of hemosiderin and silica and many ferruginous bodies; one ferruginous body was identified as having a core of anthophyllite. A granulomatous reaction was seen in two biopsy specimens and typical silicotic nodules were found in two others. The relatively brief exposure, especially in ones case (11 months), and the short latent interval before the development of the pneumoconiosis are reasons for concern for the health of iron ore workers.
PMCID: PMC1862797  PMID: 6277443
17.  Coal-workers' Pneumoconiosis 
British Medical Journal  1955;1(4923):1222.
PMCID: PMC2062097
British Heart Journal  1948;10(4):282-292.
PMCID: PMC503631  PMID: 18105879
20.  Pneumoconiosis and systemic sclerosis following 10 years of exposure to polyvinyl chloride dust. 
Thorax  1995;50(5):583-589.
The case history is presented of a 58 year old man who was exposed to thermoplastic dusts, mainly polyvinyl chloride (PVC), for 10 years. Radiography and high resolution computed tomographic scans of the lungs suggested both pneumoconiotic and scleroderma-like lesions. Transbronchial biopsy revealed foreign body granulomas with macrophages laden with birefringent inclusions which ultrastructurally resembled PVC dust. Biopsy samples of thickened skin showed histological evidence of extensive fibrosis. During follow up Raynaud's phenomenon and oesophageal involvement developed. The antinuclear antibody titre was 1:640, and the Sc1-70 subset was positive. It is concluded that exposure to PVC dust may cause pneumoconiosis and secondary systemic sclerosis.
PMCID: PMC1021235  PMID: 7597677
23.  Rheumatoid Pneumoconiosis in Association with Asbestosis 
Thorax  1964;19(5):433-435.
PMCID: PMC1018856  PMID: 14216972
24.  Rheumatoid Pneumoconiosis (Caplan's Syndrome) in an Asbestos Worker 
Thorax  1961;16(4):372-377.
PMCID: PMC1018653  PMID: 13920165
25.  Pneumoconiosis Due to Fuller's Earth 
Thorax  1961;16(2):176-179.
PMCID: PMC1018625  PMID: 13745504

Results 1-25 (290870)