We have observed that the companion shadow of the upper rib may be misinterpreted as a small pnemothorax or pleural plaque associated with asbestosis. To observe the radiographic characteristics of the normal companion shadow, we analyzed, on the posteroanterior(PA) chest radiographs, the companion shadow of 50 normal cases. Factors such as occurrence on each rib, the sharpness of the margin, the relative position to the rib, the shape and the thickness were observed. Also, we analyzed the displaced pleura of 4 pneumothorax cases to differentiate their frndings from the findings of normal companion shadows. On 50 normal chest radiographs, 192 compaion shadows were observed on the first to fourth ribs. In 173 of those shadows, the visceral margin of the companion shadow on the second rib simulated pneumothorax more closely than those on any othe rivs due to its apical location and thinness. In six of 50 normal cases, the companion shadow on the first or second rib showed an inw rdly convex lower margin, mimicking pleural plaque. The compaion shadow was suggested on the plain chest radiograph by the following characteristics imultiplicity(47/50), thicker than normal pleura(3/4), persistent on serial filma with the same shape and specific location(4/4).
Asbestosis ; Friends* ; Humans ; Pleura ; Pneumothorax ; Radiography, Thoracic ; Ribs* ; Thinness

Pulmonary asbestosis is defined as bilateral diffuse interstitial fibrosis of the lungs caused by exposure to asbestos. Many occupations are at risk for asbestos exposure, particularly in the mining, milling, manufacturing, construction, shipbuilding, and automotive industries. Therefore, the prevalence of asbestosis should be fairly widespread. The diagnosis of asbestosis can be made on either clinical or pathological grounds. We recently encountered one case of asbestosis which was confirmed histologically. On HRCT, there was ground-glass opacity with irregular linear shadows, subpleural curvilinear lines and parenchymal bands. Neither plaque nor calcification were noted. The histologic findings observed on open-lung biopsy specimen were well in accord with those in HRCT. Many asbestos-coated bodies were present along with black dust.
Asbestosis/radiography* ; Asbestosis/pathology* ; Biopsy ; Case Report ; Human ; Male ; Middle Age ; Radiography, Thoracic ; Tomography, X-Ray Computed

PURPOSE: To determine imaging findings among retired workers who were long-term exposed to asbestos. Lung and pleural diseases prevalence were studied on chest radiograph and HRCT. MATERIALS AND METHODS: Eighteen workers who were long-term exposedto asbestos occupationally in shipyards were examined by chest radiographs (PA and lateral view) and HRCT (high-resolution computed tomography). RESULTS: In 12 of 18 subjects (66.7%), asbestos-related pleural abnormalities were evident in diaphragmatic, lateral chest wall and costophrenic angle of the pleura on chest radiographs. The thickness of pleural plaques at the lateral chest wall varied. Diffuse pleural thickening was evident in 2 workers. Parenchymal abnormalities were not found on chest radiographs. On HRCT, pleural thickening wasobserved in 16 of 18 subjects (88.9%), in the areas of juxtavertebral, diaphragmatic, anterior, lateral, mediastinal and fissural pleura. Curvilinear subpleural lines representing early parenchymal asbestosis were found in the lower posterior lung in three of 18 subjects (16.7%). CONCLUSIONS: In long term asbestos-exposed workers, the asbestos-related pleural disease was 66.7% on chest radiographs and 88.9% on HRCT. The authors suggest that this group should be followed up periodically
Asbestos* ; Asbestosis ; Lung* ; Occupations ; Pleura ; Pleural Diseases* ; Prevalence* ; Radiography, Thoracic* ; Thoracic Wall ; Thorax*

Asbestosis is the most important change noted in the lung parenchyma after environmental and occupational exposure to asbestos fibers. It is characterized by diffuse interstitial pulmonary fibrosis. In Korea, the incidence of asbestosis will continue to increase for many years to come and the government enacted the Asbestos Damage Relief Law in 2011 to provide compensation to those suffering from asbestos-related diseases. Radiologic evaluation is necessary for diagnosis of asbestosis, and radiologists play a key role in this process. Therefore, it is important for radiologists to be aware of the various imaging features of asbestosis.
Asbestos ; Asbestosis* ; Compensation and Redress ; Diagnosis* ; Incidence ; Jurisprudence ; Korea* ; Lung ; Occupational Diseases ; Occupational Exposure ; Pulmonary Fibrosis ; Radiography

The classification for pneumoconiosis which was developed by International Labour Office(ILO) on the basis of Radiological findings of simple chest radiography has been widely used for the study and diagnosis of pneumoconiosis. But many problems have been revealed during the pneumoconiosis study using this classification. Those problems come from simple radiography itself or classification systems. Among those, inter-reader and intra-reader variability are the severest problems, even though many efforts have been devoted to lessen the variability. With introduction of computed tomography (conventional CT and HRCT), we are learning many new aspects about the occupational lung diseases, especially pneumoconiosis. So the studies for pneumoconiosis using tomography are reviewed, focusing on silicosis, coalworkers' pneumoconiosis, and asbestosis. But in our country, the studies of that kind are very scant. It is necessary to study and diagnose pneumoconiosis by CT, because that is the need of workers and the responsibility of physicians working in the field of occupational medicine. CT is superior to simple radiography in early detection, determination of severity, and follow-up of pneumoconiosis. But simple radiography is and should be the main method for the study and diagnosis of pneumoconiosis. Although, because of radiation hazard, cost, time, and geographical availability, the method can not and should not be used on the routine basis, we have to consider the use of CT, if possible and if necessary. Before using CT widely, we should develop the standardized criteria regarding to scanning methods and reading criteria. If not, the same problems as those of simple radiography will be occurred, and then there will be no progress in occupational medicine and workers' health.
Asbestosis ; Classification ; Diagnosis* ; Follow-Up Studies ; Learning ; Lung Diseases ; Occupational Medicine ; Pneumoconiosis* ; Radiography* ; Silicosis ; Thorax

Asbestos industry has been in operation over 60 years in Korea. However, the prevalence of asbestosis has not been yet reported. With rapid turn-over of workers, previous cross-sectional studies of current workers on the job could not find cases with exposures long enough for the development of asbestosis. This study was done to evaluate asbestosis prevalence of those worksites with operation history of more than 20 years. In total, 139 workers from 5 worksites were examined. Asbestos industries covered in the study include 2 asbestos textile, 1 brake lining, and 2 ship repairing worksites. Chest x-ray was taken from all workers and read by two exports familiar with pneumoconiosis classification according to 1980 ILO guidelines. Those with findings compatible with asbestosis were further checked with high resolution computerized tomography (HRCT). Pulmonary function tests were done according to ATS guidelines, and occupational and previous medical history was taken through a standardized interview. Air-borne asbestos was measured according to NI0SH method 7400. The air-borno asbestos concentrations ranged from 0.2-1.3 f/cc for asbestos textile, from 0.7~l.0 f/cc for brake lining, and from 6.3-7.8 f/cc during asbestos removal at ship repairing worksite. Of the 139 workers 25 had abnormal chest radiographic findings, and 10 of them had findings compatible with pneumoconiosis. When work history and current asbestos measurements were accounted, 9 workers who had more than 10 years of asbestos exposure history showed chest radiographic findings of pneumoconiosis with Finally, 4 workers showed finding of pulmonary fibrosis and/or pleural thickening at HRCT, and 2 of them had restrictive lung function changes. The study results showed that, among 139 sutjects, there were 4 (3%) definite asbeatosis cases confirmed with HRCT. The prevalence of probable asbestosis was 7% for 10-14 years of exposure, 13% for 15-19 years of exposure, and 23% for 20 or more years of exposure. The prevalence of compensable asbestosis with abnormal lung function was 4-6% for those with 15 or more years of exposure.
Asbestos* ; Asbestosis* ; Classification ; Korea ; Lung ; Pneumoconiosis ; Prevalence* ; Pulmonary Fibrosis ; Radiography, Thoracic ; Respiratory Function Tests ; Ships ; Textiles ; Thorax ; Workplace

Asbestosis is diffuse interstitial pulmonary fibrosis associated with asbestos fiber inhalation. The typical chest radiographic findings in asbestosis are small irregular or reticular opacities, predominating at the lung bases. Honeycombing is evident in more advanced diseases. But chest radiograph is relatively insensitive in detecting the presence of asbestosis. HRCT is more sensitive than simple chest radiograph for diagnosis of asbestosis, especially the early change of asbestosis. The early findings of asbestosis on HRCT are subpleural dotlike opacities and curvilinear opacities. As progression of fibrosis, intralobular interstitial thickening and interlobular septal thickening are presented. In advanced diseases, parenchymal bands, traction bronchiectasis or bronchiolectasis, and honeycombing are noted. These findings are typically located in lower posterior subpleural portions with bilateral symmetric patterns. Imaging findings that are compatible with asbestosis, rale, and a reduced diffusing capacity can increase confidence of diagnosis of asbestosis.
Asbestos ; Asbestosis ; Bronchiectasis ; Fibrosis ; Inhalation ; Lung ; Pulmonary Fibrosis ; Radiography, Thoracic ; Respiratory Sounds ; Thorax ; Tomography, X-Ray Computed ; Traction

OBJECTIVETo evaluate the feasibility of direct digital radiography (DDR) in the diagnosis of asbestosis, and to analyze the difference and similarity between DDR and film-screen radiography (FSR) in terms of the radiographic features of asbestosis.

METHODSA total of 60 cases of asbestosis underwent FSR and DDR of the chest in the same day. The FSR and DDR findings were compared with respect to shapes and profusion of small opacities, pleural abnormality, and diagnostic stages.

RESULTSThe patients showed "s", "t", and "p" small opacities on chest images, with irregular "s" and "t" ones predominating (FSR: 95.0%; DDR: 91.7%). The small opacities were widely distributed in six lung zones, especially in middle and lower zones. The shapes and distribution of small opacities did not differ significantly between FSR and DDR findings (P > 0.05). For all the 60 cases, the two radiographies demonstrated a concordance rate of 64.2% (231/360) for the profusion of small opacities in lung zones (κ = 0.62, 95%CI: 0.54 ∼ 0.69), and for the 43 cases (258 lung zones) who displayed identical small opacity shapes on the two radiographies, the concordance rate was 81.0% (209/258) (κ = 0.79, 95%CI: 0.72 ∼ 0.87). FSR revealed 10 cases (16.7%) of pleural thickening, compared to 12 cases (20.0%) on DDR (P > 0.05). FSR revealed 53 cases (88.3%) of stage I asbestosis and 7 cases (11.7%) of stage II asbestosis, compared to 51 cases (85.0%) and 9 cases (15.0%) on DDR (P > 0.05). There was no significant difference in diagnostic stages between the two radiographies (P > 0.05), demonstrating a concordance rate of 93.3% (56/60) (κ = 0.71, 95%CI: 0.45 ∼ 0.98).

CONCLUSIONDDR is similar to FSR in determining the shapes, distribution, and profusion of small opacities, pleural abnormality, and diagnostic stages.

Aged ; Aged, 80 and over ; Asbestosis ; diagnostic imaging ; Female ; Humans ; Male ; Middle Aged ; Radiographic Image Enhancement ; Radiography, Thoracic ; methods

Asbestos related pleuropulmonary disease has been emerging health problem for recent years. It can cause variable clinical symptoms and radiological abnormalities. However, there has been no report for their characteristics in subjects who were environmentally exposed to asbestos. We reviewed the CT images of 35 people who were environmentally exposed to asbestos in Chungnam province, Korea. The study result showed high incidence of pleural plaque and pulmonary fibrosis on chest CT (94% and 77%, respectively). The common CT findings of lung parenchymal lesions were as follows: centrilobular opacities (94%), subpleural dot-like or branching opacities (80%), interlobular septal thickening (57%), intralobular interstitial thickening (46%), parenchymal bands (43%) and subpleural curvilinear line (29%). There were no significant differences in the prevalence of pulmonary fibrosis and pleural plaques according to sex, age and duration of exposure. In conclusion, pleural plaque and pulmonary fibrosis are common asbestos-related CT finding in the exposed people. Asbestos related lung parenchymal CT findings in the participants with environmental exposure show similar to those observed in the occupational exposure.
Adult ; Aged ; Aged, 80 and over ; Asbestos/*adverse effects ; Asbestosis/epidemiology/etiology/*radiography ; Environmental Exposure/*adverse effects ; Female ; Humans ; Male ; Middle Aged ; Multidetector Computed Tomography ; Pleura/radiography ; Prevalence ; Republic of Korea/epidemiology

OBJECTIVE: This study evaluated the CT characteristics of pleural plaques in asbestos-exposed individuals and compared occupational versus environmental exposure groups. MATERIALS AND METHODS: This study enrolled 181 subjects with occupational exposure and 98 with environmental exposure from chrysotile asbestos mines, who had pleural plaques confirmed by a chest CT. The CT scans were analyzed for morphological characteristics, the number and distribution of pleural plaques and combined pulmonary fibrosis. Furthermore, the CT findings were compared between the occupational and environmental exposure groups. RESULTS: Concerning the 279 subjects, the pleural plaques were single in 2.2% and unilateral in 3.6%, and showed variable widths (range, 1-20 mm; mean, 5.4 +/- 2.7 mm) and lengths (5-310 mm; 72.6 +/- 54.8 mm). The chest wall was the most commonly involved (98.6%), with an upper predominance on the ventral side (upper, 77.8% vs. lower, 55.9%, p < 0.001) and a lower predominance on the dorsal side (upper, 74.9% vs. lower, 91.8%, p = 0.02). Diaphragmatic involvement (78.1%) showed a right-side predominance (right, 73.8% vs. left, 55.6%, p < 0.001), whereas mediastinal plaques (42.7%) were more frequent on the left (right, 17.6% vs. left, 39.4%, p < 0.001). The extent and maximum length of plaques, and presence and severity of combined asbestosis, were significantly higher in the occupational exposure group (p < 0.05). CONCLUSION: Pleural plaques in asbestos-exposed individuals are variable in number and size; and show a predominant distribution in the upper ventral and lower dorsal chest walls, right diaphragm, and left mediastinum. Asbestos mine workers have a higher extent of plaques and pulmonary fibrosis versus environmentally exposed individuals.
Adult ; Aged ; Aged, 80 and over ; Asbestos, Serpentine/*toxicity ; Asbestosis/*etiology/radiography ; Asian Continental Ancestry Group ; Environmental Pollutants/toxicity ; Female ; Humans ; Male ; Middle Aged ; Mining ; Occupational Exposure ; Pleural Diseases/*etiology/radiography ; Republic of Korea ; Tomography, X-Ray Computed