Search

It has been stated that 'The interpretation of films for pneumoconiosis requires profound knowledge and perspicacity and that the ideal interpreter is a happy blend of Sherlock Holmes, Albrecht Durer [...]

A retrospective study was conducted in 23 subjects with previous occupational exposure to asbestos and exhibiting rounded atelectasis (RA) on high-resolution computed tomography scan (HRCT scan) to evaluate the retention [...]

Asbestosis is a lung disease that is caused by prolonged exposure to asbestos fibers. Once inside the lungs, the fibers scar and damage the lung tissue, and cause a thick and dense layer of tissue to form in the lungs. This condition, called fibrosis, makes breathing difficult because it reduces the elasticity of the lungs, making them harder to inflate, and it reduces the ability to exchange oxygen and carbon dioxide across lung membranes. Asbestosis is serious because there is no treatment for it. A work-related history of prolonged exposure to large amounts of asbestos and lung tests that clearly show that fibrosis is present are needed to make a definite diagnosis of asbestosis. This is important because workers with lung symptoms who have had more limited exposure to asbestos may have a different type of lung disease that is less severe than asbestosis and may be treatable. In a study including 176 workers who were exposed to asbestos, nine were diagnosed as having asbestosis. In a longitudinal study of 1,764 workers exposed to asbestos, there were no cases of asbestosis over a 30-year period. These findings indicate that the number of cases of asbestosis is decreasing. Therefore, an accurate diagnosis in asbestos workers with lung symptoms is crucial in determining what type of lung disease may be present and what type of treatment should be used. (Consumer Summary produced by Reliance Medical Information, Inc.)

Asbestosis is a lung disorder characterized by the development of diffuse interstitial fibrosis, resulting from the inhalation of asbestos fibers. For the patient, this diagnosis usually includes a dim prognosis, limited work ability, and, sometimes, monetary compensation. The precise definition of this disease and a differential diagnosis is essential for the appropriate treatment, as well as the psychological health and future of the patient. In addition to the traditional diagnostic criteria including exposure, carbon monoxide diffusing capacity, forced vital capacity measurements, and X-ray imaging, other lung and pulmonary function tests should be considered; these include CT scans, bronchoalveolar lavage and gallium scan, and examination of pulmonary fluids for fibers and ferruginous bodies. The correct interpretation of the test findings is critical to a correct diagnosis. Each of the diagnostic criteria are reviewed in detail, and findings that contravene a diagnosis of asbestosis are described. (Consumer Summary produced by Reliance Medical Information, Inc.)

Breathing asbestos particles results in a major risk of lung problems, including cancer. It is thought that an early indication of lung damage caused by asbestos is lesions in the airways. Early detection of asbestosis is important in treating and preventing further damage of the lungs, but it is difficult using conventional X-rays. This study looked at the use of high-resolution computed tomography (CT) to detect early damage in the lungs. The study involved 23 patients with known exposure to asbestos. Regular X-rays were normal. CT was then performed on the patients, with a second scan performed up to 37 months later. Results of CT showed abnormalities in 21 of the 23 patients. Among the abnormalities were thickened intralobular lines, micronodules, hazy patches, subpleural curvilinear lines, small cystic spaces, and small areas of low attenuation (thinning). In 21 of the patients, subpleural dots were seen on the initial CT, which had become enlarged in 10 of these patients by the time of the later CT. In comparing the first with the second examination, regular X-rays showed a progression in disease in five patients, while CT found progression in nine patients. The results of this study indicate not only that high-resolution CT is better able to detect early asbestosis, but that it may also be useful in characterizing the progression of the disease. However, the study was small and a larger study group is needed to further characterize the progression of asbestosis. (Consumer Summary produced by Reliance Medical Information, Inc.)

The scanning electron microscope (SEM) is an instrument that bombards the surface of prepared samples with electrons. As a result of this bombardment, electrons and X-rays are emitted by the surface of the sample, and their quantity and energy level can be used to reconstruct the appearance of the object at high magnification. When the energies of the emitted X-rays are studied, it is possible to detect specific molecules and their approximate percent composition; this is called energy-dispersive X-ray analysis, or EDXA. SEM and EDXA were used to examine biopsy samples taken from 25 patients who had lung disease diagnosed as idiopathic (unknown origin) pulmonary fibrosis (IPF). The results from these analyzes were compared with samples from 25 autopsy subjects with normal lungs, and with samples of lung tissue taken from six patients diagnosed with pneumoconiosis (two with silicosis, three with asbestosis, and one with coal miner's lung). Pneumoconiosis is an environmentally-caused disease where degenerative lung changes (fibrosis) accompany exposure to and retention of certain minerals, such as silicon, asbestos, and carbon. Approximately one-half of the patients diagnosed with IPF had suspiciously high levels of silicone in their lung samples compared with levels of sulfur (the ratio Si/S greater than 0.3). Further, approximately half of the group with a Si/S ratio that exceeded 0.3 also had an exposure history which was presumptive for the inhalation of silica or silicates. The correct diagnosis for these patients is probably pneumoconiosis. This study suggests that SEM and EDXA are important in obtaining accurate diagnoses in such cases. (Consumer Summary produced by Reliance Medical Information, Inc.), Mineralogical Microanalysis of Idiopathic Pulmonary Fibrosis DURING the last two decades, advances in mineralogical analysis have enabled its application in pneumology. [1-4] Among the techniques applicable to organic matter, scnanning [...]

Methods of diagnosis and treatment of diffuse parenchymal lung diseases are described. The different conditions within the group of diseases, the main causes of the disease, and treatment or surgery options are explained.

(CHEST 1997; 111:1424-26) Millions of workers have had occupational exposure to asbestos throughout the last century. While the literature is replete with descriptions of asbestos-related disorders, it is difficult to [...]

Surveillance of personnel who have known or suspected asbestos fiber exposure is an ongoing process. The principal diagnostic tool available for this purpose is the chest X-ray. The presence of irregular or linear opacities in the bases of the lungs and/or the presence of bilateral pleural thickening on the chest wall or diaphragm are considered to be diagnostic features consistent with asbestos and asbestiform mineral exposure. In 1986, approximately 750 retired and employed tireworkers at a specific site were interviewed about pulmonary symptoms, smoking habits, occupational history. They were also given a medical examination which included chest X-rays and spirometry (to measure the air capacity of the lungs). Approximately 440 of those examined filed claims for asbestos-related injury, based on the findings of the questionnaire responses and evaluation of the chest films. This proportion of persons would have suggested a 60 percent prevalence of asbestos-related injury, indicative of an epidemic of extraordinary proportions. Three independent radiologists reevaluated the chest X-rays without knowledge of the purpose of the study or previous diagnoses, and without consulting with each other. Individually, they determined that 3.7 percent, 3.0 percent and 2.7 percent of the tireworkers had asbestos-related injury. Sixteen cases were suspected but, after further review, only 11 cases (2.5 percent) were finally diagnosed as having injuries consistent with exposure to asbestiform minerals. One reason why so many chest X-rays were initially categorized as indicative of asbestos injury is that most of the tireworkers were over 50 years of age and may have developed pulmonary changes, due to other causes, that could produce similar X-ray images. (Consumer Summary produced by Reliance Medical Information, Inc.)

The pattern of pleural calcification and the patient's history are helpful in determining the usually remote cause of the calcification. Here, Drs Mahesh Duggal, Achal Dhupa, Krishna Badhey, and Arunabh [...]

Purpose: To assess alveolitis as measured by Gallium-67 scanning in asbestos-exposed subjects and its relation to patient characteristics, asbestos exposure variables, smoking, chest x-ray and pulmonary function. Methods: 179 consecutive [...]

In 1976 a survey of 2,245 asbestos miners was conducted in South Africa in order to detect the presence of small irregular opacities (IOs) on radiographs (X-rays). IOs are believed to indicate the presence of asbestosis. X-rays were taken an average of 5.7 years prior to a miner's death. This allowed time for asbestosis to develop after the X-ray. The goal of the study was to estimate the frequency of false positive diagnosis of asbestosis based on the presence of a radiographic IO. Detailed information about asbestos, mining and miner's habits and physical characteristics (smoking, age, height, weight) were examined to determine the impact of these factors as possible causes of false positive radiographic interpretations. Researchers believe that dust exposure and smoking are possible factors that contribute to false positive interpretations, but that obesity and age are not. They emphasize that more research regarding the interpretation of IOs found on the radiographs of asbestos workers is needed.

Gallium lung scanning is widely used to evaluate pulmonary inflammation in patients with interstitial lung disease but has not previously been reported in crocidolite-exposed workers. In order to characterize the [...]

(CHEST 1997; 111:1427-28) The preceding essay 'Asbestos-Related Disorders: A Realistic Perspective' explores the diagnostic uncertainty confronting the clinician when asked by the asbestos-exposed patient, 'Do I have asbestosis?' Little has [...]

Benjamin F. Withers, M.D., M.P.H.;[unkeyable] Alan M. Ducatman, M.S., M.D.;[unkeyable] and CDR William N. Yang, MC, USN Section The roentgenographic prevalence and anatomic distribution of pleural plaques were studied in [...]