[The investigation of clinical images of 88 hospital staff with SARS]

OBJECTIVE

To investigate the clinical thoracic images of hospital staff with SARS.

METHODS

Thoracic images was analyzed in 88 medical workers with SARS, including 394 chest plain films and 9 CT scans.

RESULTS

The typical signs of SARS are multifocal air-space consolidations, and progress over a day from small shadow to becoming generalized.

CONCLUSION

Thoracic plain film was necessary for diagnosis of SARS, CT could detect the pulmonary abnormality of SARS early.

Cervical spine degenerative changes (narrowed intervertebral disc spaces and osteophytes) in coal miners

A series of 685 x-ray films of the cervical spine obtained in coal miners was analyzed to explore the occurrence of narrowed disc spaces and osteophytes in this occupational group, and to examine the association of x-ray changes with age, duration of employment, and duration of occupational exposure to hand-arm vibration. All data were extracted from individual medical files of coal miners examined for suspected hand-arm vibration-related disorders in 1989-1999 at the Occupational Medicine Center in Katowice. The narrowed intervertebral disc spaces were found in 188 coal miners (26.9%) and osteophytes in 332 coal miners (47.5%). The occurrence of degenerative changes in coal miners was similar to that observed in a small group of 68 blue-collar workers (no exposure to hand-arm vibration) employed in the coal industry. Univariate comparisons showed that narrowed intervertebral disc spaces and osteophytes were more frequent among older subjects and among subjects with longer duration of employment. The prevalence of changes also showed some relationship with the number of years of exposure to hand-arm vibration. The results of logistic regression analysis confirmed statistically significant effect of age, but not of other factors included in the model. When both x-ray changes were grouped together (a combined dependent variable) age remained the only statistically significant explanatory variable. The findings do not support the view that the examined degenerative changes in the cervical spine are more prevalent in coal miners and depend on duration of physical work or local exposure to hand-arm vibration in this occupational group.

[Occupational disease 2108. Degenerative changes of the cervical spine as a causality criterion in the assessment of discogenic diseases according to BeKV 2108]

With the second amendment to the Ordinance on Occupational Diseases (BeKV) of 18 December 1992, discogenic diseases of the spine are included in the disease register of occupational diseases for the first time. If occupations that impose stress on the spine have been practised for many years, the possibility exists of recognizing degenerative diseases as an occupational disease. In assessment practice, the radiological data on the spine exposed to stress is compared with that of regions which are remote from the stress (cervical/thoracic spine). This pattern of the distribution of degenerative disease is then used as the basis for determining a causal relationship between the occupation causing the stress and disease of the axial skeleton. The pattern of degeneration of the cervical spine was investigated in two groups, one with ( n =153) and one without ( n =333) occupations that impose stress on the lumbar spine. A cumulative score of degenerative changes was elaborated and presented as a new classification. No differences were found between the groups with regard to either the frequency of occurrence, segmental distribution or severity of disease. In both groups, degenerative changes correlated with age. The prevailing assessment practice is discussed on the basis of these data.

[Lipoid pneumonia related to workplace exposure to paint]

A 49-year-old man with no known history of pulmonary disease was treated at our hospital after observation of an interstitial pattern on a chest film. The patient was a smoker and professional painter. Computed tomography of the chest showed a diffuse bilateral ground-glass pattern. The lung biopsy showed intra-alveolar lipid accumulation in the form of vacuoles of varying sizes surrounded by numerous focally multinucleated macrophages, establishing a definitive diagnosis of exogenous lipoid pneumonia. Given the patient's profession, he was recommended to avoid workplace exposure to paraffins and oily sprays. The clinical course was favorable after exposure was stopped, with improved lung function and symptoms.

Chest radiological findings in Pakistani cement mill workers

OBJECTIVE

Even in the 21st century, in developing countries millions of people work daily in dusty environments. They are exposed to different types of health hazards namely, fumes, gases and dust, which are risk factors for developing occupational diseases. Therefore, the aim of this study was to perform chest radiology to determine the occupational hazards of cement dust on the lungs of cement mill workers.

METHODS

This study was carried out in the Department of Physiology, Faculty of Health and Medical Sciences, Hamdard University Karachi, Pakistan, during the period June to August 2000. In this study 50, apparently healthy volunteer male cement mill workers were randomly selected with an average of 13 years exposure with age ranging from 20-60 years. They were matched with 50, healthy male control subjects in terms of age, height, weight and socioeconomic status. Both groups met with exclusion criteria as per standard. Radiology was performed by Trophy radiology.

RESULTS

The present study demonstrated 12% of cases with interstitial lung disease and 2% of cases with pleural thickening and chronic bronchitis in cement mill workers.

CONCLUSION

Exposure to cement dust causes interstitial lung disease, pleural thickening and chronic bronchitis in cement mill workers.

[Flexor tendoplasty with a tendon prosthesis for zone II flexor tendon injuries]

OBJECTIVES

We evaluated two-staged flexor tendoplasty with tendon prosthesis in patients with flexor tendon injuries in which conventional tendon grafting would fail to yield an acceptable result.

METHODS

We performed flexor tendoplasty with tendon prosthesis in 37 hands of 31 patients (24 males, 7 females; mean age 23 years; range 4-46 years). Twenty-six patients had penetrating injuries, four had occupational injuries, and one patient had an electric burn. Preoperatively, all patients were evaluated according to the Boyes' classification. At the first stage, a silicone prosthesis, 4-6 mm in diameter was placed according to the patient's age and the recipient bed; after 3 to 5 months, silicone prosthesis was removed and flexor tendoplasty with a tendon graft was performed. The results were calculated according to the Strickland's formula. The mean follow-up period after the second operation was 37 months (range 12-80 months).

RESULTS

The results were excellent in 11 hands (Strickland 75-100%), good in 15 hands (50-74%), moderate in nine hands (25-49%), and poor in two hands (0-24%), with a mean of 58%. Tenolysis was performed in seven patients at least four months after the second stage. Removal of the tendon prosthesis was required in one patient because of infection.

CONCLUSION

Satisfactory results can be obtained with two-staged flexor tendoplasty with a tendon prosthesis in patients with joint injuries restricting finger movements, digital nerve injuries causing trophic changes in the finger, and multiple tissue injuries.

[Some aspects of occupational spinal diseases]

Prevalence of neurologic cervical and lumbar disorders among workers does not depend upon hardness of work conditions. First diagnosed occupational vertebral syndromes were clinically divided into reflectory and compression ones. Length of service, age and X-ray signs appeared not to differ significantly between the groups.

Periportal fibrosis and other liver ultrasonography findings in vinyl chloride workers

AIMS

To investigate the presence of liver lesions and their relation with vinyl chloride monomer (VCM) exposure or other personal risk factors, in workers involved in the production of VCM and polyvinyl chloride (PVC).

METHODS

A liver ultrasonography examination was conducted in 757 workers, some of whom had long standing service in the production of VCM and PVC. The study involved: assessment of individual past and present VCM exposure of each worker; collection of past personal health history, lifestyle and personal data; routine liver function tests; and liver ultrasonography.

RESULTS

No cases of liver malignancies were detected. Angiomas and liver cysts were found with a frequency of occurrence within the expected range of the general population. The main findings consisted of hepatomegaly (34.7%), steatosis (31.8%), and periportal fibrosis (16.0%). A logistic regression analysis indicated that hepatomegaly and steatosis were associated with obesity and lipid metabolism disturbances and not with VCM exposure. Periportal fibrosis, in addition to constitutional or dietary factors, was shown to be associated with VCM exposure, but only when maximum exposure in the subject's history had been at least 200 ppm as a yearly average; no effects were observed at 50 ppm or below.

CONCLUSIONS

Workers exposed to 200 ppm VCM for at least one year have a fourfold increased risk of developing periportal liver fibrosis. Liver ultrasonography is a suitable and important diagnostic test for the medical surveillance of vinyl chloride workers.

Silicosis and lung function decrements among female ceramic workers in Italy

It is well known that male ceramic workers have elevated risks of chronic silicosis. The objective of this study was to assess whether female ceramic workers also have an increased risk of silicosis and whether these women have decreased lung function related to silica exposure. Ceramic workers from Civitacastellana, Italy, were enrolled in health surveillance during the 1970s. A total of 642 women were under surveillance; a respiratory monitoring program was conducted from 1974 to 1987, with follow-up through 1991 that included annual chest radiography and measurement of lung function. Radiography findings were defined as silicosis if the chest films were > or =1/0 with small, rounded opacities. Multiple linear regression models for repeated measures (generalized estimating equations) were run to evaluate associations of forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV(1)) with years of exposure and radiograph opacities. Nine cases of silicosis were identified on the basis of radiographic evidence. Silicosis risk was not associated with smoking but was related to employment before 1970 and demonstrated a dose-response gradient for years of exposure. FVC and FEV(1) both showed significant (p < 0.05) associations with duration of exposure and with positive radiography findings. The results for female ceramic workers are consistent with those for male employees regarding exposure to fibrogenic dusts.

[Findings in a high-risk group following asbestos exposure. Benefit of ENT examinations in patients with long-term exposure to asbestos]

BACKGROUND AND OBJECTIVE

Laryngeal diseases caused by exposure to asbestos are listed in the current German list of occupational diseases under number 4104. Parallel to a multicenter study to evaluate whether a CT scan should be included in the examinations for occupational diseases according to the German surveillance guidelines, an additional ENT examination was evaluated.

PATIENTS AND METHODS

One hundred workers with a mean exposure time to asbestos of 20.9 years were given a complete ENT examination in 4 consecutive years (1993-1996). Radiological signs for asbestosis were observed in 21 cases and 58 participants had pleural affections caused by asbestos. Significant nicotine abuse was reported by 15 persons: 61 participants were ex-smokers and 24 had never smoked. Regular alcohol consumption was reported by 90% (11% more than 80 g/day).

RESULTS

As documented in the literature, we found a high prevalence of laryngitis, especially in smoking patients. One patient had early laryngeal cancer (T1).

CONCLUSION

The integration of an ENT examination into the German surveillance guidelines for occupational diseases should be discussed for patients with a high exposure to asbestos.

Hard metal interstitial lung disease: high-resolution computed tomography appearance

Hard metal interstitial lung disease (HM-ILD) is a rare form of interstitial lung disease caused by aerosolized particulates containing cobalt inhaled during the manufacture or grinding of hard metal. The high-resolution computed tomography (HRCT) appearance of HM-ILD includes reticulation, traction bronchiectasis, and large peripheral cystic spaces in a mid and upper lung distribution. This appearance, along with a consistent occupational exposure, should specifically suggest the diagnosis of HM-ILD.

Chronic interstitial pneumonia with honeycombing in coal workers

BACKGROUND

Coal worker's pneumoconiosis (CWP) results from coal mine dust inhalation.

PATIENTS AND METHODS

We report here the presence of a chronic interstitial pneumonia (CIP) with honeycombing in 38 cases of coal miners, with or without CWP. The 38 patients were selected on the basis of clinical criteria which are unusual in CWP, i.e. fine inspiratory crackles and severe dyspnea. There were 37 men and one woman; mean age was 67.5 +/- 9.1 years. Thirty-two were smokers. Duration of exposure was 26.7 +/- 9.9 years. All the patients had clinical examination, chest radiography, computed tomography (CT), lung function, laboratory investigations, wedged fiberoptic bronchoscopy with bronchoalveolar lavage (BAL). In eight cases, lung specimens were obtained (lung biopsy n = 6, explanted lungs n = 2).

RESULTS

Seventeen out of 38 had finger clubbing. 17 had radiological signs of CWP limited to the upper lobes (n = 11) or diffusely distributed (n = 6). CT showed honeycombing (36 cases), and/or ground glass opacities (30 cases) with traction bronchiectasis (8 cases) predominant in the lower lobes. BAL analysis demonstrated an increased percentage of neutrophils (9.4% +/- 6). Lung function showed a restrictive pattern (TLC = 75.1% +/- 16 and FVC = 79.7% +/- 17 of predicted values) associated with a decreased DLCO (50.4 % +/- 22.9 of predicted values) and hypoxemia (at rest = 65.9 mmHg +/- 13.5, upon effort = 56.5 mmHg +/- 13.4). Lung specimens demonstrated in 2 cases a homogenous interstitial fibrosis of intra-alveolar septum with an accumulation of immune and inflammatory cells without temporal variation and with obvious honeycombing. The 6 other cases showed features of usual interstitial pneumonia.

CONCLUSION

In presenting these cases, we would like to alert other clinicians to a possible association between CIP with honeycombing and coal dust exposure, with or without associated CWP.

[Is lumbar disk disease an occupational disease? Scientific background, radiological findings, and medical legal interpretations]

AIM

It should be cleared whether or not the interpretation of lumbar disk disease as an occupational disease is justifiable. Which disc changes follow whole-body vibration and can they be distinguished from those which occur constitutionally while aging?

METHOD

Orthopedic meta-analysis of epidemiological and occupational studies concerning the influence of whole- body vibration.

RESULTS

Reliable studies are rare. Severe methodological problems limit the interpretation of difficult relationships. The role of age when working influences begin as well as the stress and behaviour of exposed persons away from the work-place before and while working with whole-body vibration is not known. There is no study which could be called exact according orthopedic criteria. It is therefore not evident that whole-body vibration causes lumbar disc disease.

CONCLUSIONS

After whole-body vibration similar to long term heavy lifting an earlier beginning of disk degeneration in X-ray-studies can be observed. This leads to prevalence differences, which diminish with increasing age. Deviation to the left of the prevalence curve lasts for five to ten years. Whole-body vibration leads to a topographic modification of disk degeneration of the lumbar spine. After long duration exposition an increased amount of spondylotic changes at the thoracolumbar junction and the middle half of lumbar spine can be observed (up to the upper plate of the fourth vertebral body). This can be explained by biomechanic means: whole-body vibration caused by tractor driving and similar long-term exposures leads to traction of the disks of the lower thoracic spine and the upper and middle parts of lumbar spine.

Longitudinal analyses of chest radiographs from the European Carbon Black Respiratory Morbidity Study

High levels of exposure to carbon black have been linked with an increased prevalence of chest radiograph abnormalities. However, it is unclear to what extent current levels of exposure in the carbon black manufacturing industry are associated with new cases of and progression in small opacities. Longitudinal analyses were carried out on data from workers in the European carbon black manufacturing industry who provided three full-size chest radiographs sequentially between 1987-1995. All chest radiographs were independently read by three experienced readers according to the International Labour Organisation (ILO) classification. After exclusion of participants with previous lung diseases or injuries, females, unreadable chest radiographs and from factories with a low participation rate, data from 675 workers were available for the longitudinal analyses. An association was observed between cumulative carbon black exposure and new cases of chest radiograph abnormalities (ILO category > or = 1/0) and progression in small opacities. These associations were mainly related to changes in chest radiographs from workers at one factory. A large percentage of workers with chest radiograph abnormalities reversed to normal chest films; however, after adjusting for other factors, this was not associated with levels of exposure to carbon black dust. In conclusion, the results show that exposure to carbon black is associated with increased risk of chest radiographic abnormalities, which may be reversible after reduction or cessation of exposure.

[Bilateral necrosis of the femoral head after use of working harness]

The case of a 42-year old man, who developed bilateral necrosis of the femoral head from traumatic causes is described. He hung in stirrups, working 4-6 hours a day decorating for three weeks, during which he complained of numbness, fatigue and radiating pain in both legs. X-rays and a bone scan were performed and bilateral femoral head necrosis was diagnosed, probably because of repeated temporary hypoxia of the femoral heads caused by the stirrups compressing the blood vessels.

Imaging of thoracic occupational and environmental malignancies

The imaging features of occupational lung cancer are similar to those of nonoccupational cancer. Occupational lung cancer in patients with asbestos exposure must be differentiated from mimics such as round atelectasis and fissural pleural plaques. Mesothelioma remains a largely incurable tumor, though treatment options are expanding. CT, MRI, and PET scanning may all have complementary roles in staging mesothelioma.

International Labor Office Classification System in the age of imaging: relevant or redundant

The 1980 International Labor Office International Classification of Radiographs of Pneumoconioses is a widely used epidemiologic tool with a storied past. This article reviews its development and examines its applications to occupational lung disease and the controversies generated in that process. The question of its relevancy to current imaging practices is discussed.

A longitudinal study of chest radiographic changes of workers in the refractory ceramic fiber industry

STUDY OBJECTIVE

This industry-wide longitudinal study examines chest radiographic changes of workers manufacturing refractory ceramic fibers (RCF).

DESIGN

Chest radiographs were obtained every 3 years and were interpreted using the 1980 International Labour Organization classification for pneumoconiosis. Three exposure metrics were calculated: duration and latency in a production job, and cumulative exposure (fiber-months per cubic centimeter).

PARTICIPANTS

The radiographic survey included 625 current workers at five manufacturing sites and 383 former workers at two of the five sites.

MEASUREMENTS AND RESULTS

Pleural changes were seen in 27 workers (2.7%). Of workers with > 20 years of latency from initial production job or 20 years of duration in a production job, 16 workers (8.0%) and 5 workers (8.1%) demonstrated pleural changes, respectively. Results from the cumulative exposure analysis (> 135 fiber-months per cubic centimeter) demonstrated a significant elevated odds ratio (OR) of 6.0 (95% confidence interval [CI], 1.4 to 31.0). The incidence of irregular opacities at profusion categories > or = 1/0 was similar to other nonspecified dust-exposed worker populations at 1.0%, and showed a nonsignificant elevated OR in regard to cumulative fiber exposure of 4.7 (95% CI, 0.97 to 23.5).

CONCLUSIONS

RCF are significantly associated with pleural changes that were predominantly pleural plaques, but have not resulted in a statistically significant increase in interstitial changes.

Respiratory morbidity in a population of French dental technicians

AIMS

To compare wage earner dental technicians with non-exposed salaried subjects for the prevalence of respiratory symptoms and function, and chest x ray abnormalities.

METHODS

A total of 134 dental technicians and 131 non-exposed subjects participated. A medical and an occupational questionnaire were filled in to evaluate the prevalence of respiratory symptoms and occupational exposures. Subjects underwent respiratory tests and chest x ray examination.

RESULTS

Mean age of the dental technicians was 36.6 years with a mean duration of dental work of 16.5 years. There was a significant risk of cough (day and night) and usual phlegm in dental technicians. Respiratory function parameters were lower in dental technicians with a significant difference between exposed and non-exposed groups for % FVC (forced vital capacity), % FEF(25) (forced mid expiratory flow), and % FEF(50). The prevalence of small opacities increased with age. Small opacities were significantly related to an exposure to asbestos in the past.

CONCLUSIONS

Our young population of dental technicians is at risk of respiratory morbidity. They should benefit from adequate technical prevention measures.

Singing paraplegia: a distinctive manifestation of a spinal dural arteriovenous fistula

The unique case of a baritone with a spinal dural arteriovenous fistula (SDAVF) causing recurrent, acute paraplegia during singing is described. This case underscores the presence of impaired venous drainage in these lesions and the high level of clinical suspicion required for their diagnosis in patients with any myelopathy.

Inhalational anthrax after bioterrorism exposure: spectrum of imaging findings in two surviving patients

The radiographic and computed tomographic (CT) findings in two patients with documented inhalational anthrax resulting from bioterrorism exposure are presented. Chest radiographs demonstrated mediastinal widening, adenopathy, pleural effusions, and air-space disease. Chest CT images revealed enlarged hyperattenuating mediastinal and hilar lymph nodes and edema of mediastinal fat. Chest CT findings are helpful for making the initial diagnosis. To the authors' knowledge, the spectrum and follow-up of CT findings have not been previously described.

High-resolution CT in the evaluation of occupational and environmental disease

The most common of the pneumoconioses are silicosis, CWP, and asbestosis. The former two are characterized by the presence of small nodular opacities predominantly distributed in the upper zones of the lung. The small nodular opacities are classified into two patterns on HRCT: (1) ill-defined fine branching lines and (2) well-defined discrete nodules. Asbestosis demonstrates thickened interlobular and intralobular lines, subpleural dot-like or curvilinear opacities, and honeycombing on HRCT, predominantly distributed in the bases of the lungs. Although HRCT findings of other pneumoconioses are variable and nonspecific, there are predominant and characteristic findings for each type of pneumoconiosis. HRCT is useful in achieving more accurate categorization of the parenchymal changes in each type of pneumoconiosis.

Imaging of occupational lung disease

Occupational lung disease comprises a wide variety of disorders caused by the inhalation or ingestion of dust particles or noxious chemicals. These disorders include pneumoconiosis, asbestos-related pleural and parenchymal disease, chemical pneumonitis, occupational infection, hypersensitivity pneumonitis, and organic dust toxic syndrome. Most of these disorders produce diffuse lung disease. Although many of the disorders can be detected at chest radiography, high-resolution computed tomography (CT) has been shown to be superior to chest radiography in depicting parenchymal, airway, and pleural abnormalities. Some occupational lung diseases have characteristic radiologic features suggesting the correct diagnosis, whereas in others, a combination of clinical features, related occupational history, radiologic findings, and literature supporting an association between the exposure and the disease process is required for diagnosis. With advances in chest radiology, including high-resolution CT, radiologists play a key role in the clinical evaluation of occupational lung diseases and should continue their involvement in the diagnosis and treatment of these diseases.

Reliability and validity of chest radiograph surveillance programs

STUDY OBJECTIVES

Due to the lack of consensus in the literature in the use of posteroanterior (PA) vs PA with right and left oblique views as the optimum radiograph surveillance methodology to investigate pleural changes, a study was undertaken to evaluate the reliability, sensitivity, and specificity of these two approaches.

DESIGN

Three experienced radiologist B readers used the 1980 International Labor Office classification system for pneumoconiosis to independently read chest radiographs of workers with individual identifiers masked. All radiographs were read first as a PA view only. Unknown to the B readers, each subject's PA was then matched to his or her corresponding right and left oblique views (film triad) and re-read several weeks later.

SETTING AND PARTICIPANTS

The respiratory health of 652 workers exposed to refractory ceramic fiber was assessed as part of cross-sectional and longitudinal surveillance programs.

MEASUREMENTS AND RESULTS

kappa Statistics for interreader and intrareader reliability between the PA view and film triad methods were calculated. Sensitivity, specificity, and positive predictive value were assessed by comparing the initial cross-sectional study to the longitudinal study. The film triad method had considerably higher interreader reliability (kappa = 0.59) compared to the PA-only method (kappa = 0.44). Results from the initial cross-sectional study were then compared to findings evaluated longitudinally. The film triad again was superior, demonstrating a positive predictive value of 73.7% compared to only 47.8% for the PA method.

CONCLUSIONS

It is our recommendation that the film triad method be used in surveillance studies where both parenchymal and pleural changes are anticipated.

Extrinsic allergic alveolitis from a proteolytic enzyme

BACKGROUND

Subtilisins are proteolytic enzymes of bacterial origin found in detergents. They are high-molecular-weight antigens and have been implicated in allergic rhinitis and asthma.

OBJECTIVE

This report describes a case of extrinsic allergic alveolitis due to subtilisins in a liquid cleaner.

METHODS

Clinical, radiologic, and serologic information were used to make the diagnosis.

CASE REPORT

A 53-year-old woman developed respiratory symptoms while working with a cleaner containing subtilisins. Her symptoms intensified in the work environment and improved away from work. A computed tomography scan demonstrated alveolar and interstitial infiltrates with subsequent scarring. A pulmonary function study revealed a restrictive pattern with diminished diffusion capacity. Bronchoalveolar lavage showed lymphocytosis and all cultures were negative. Precipitating antibodies to the enzyme were found in the patient's serum. Her symptoms improved once she changed her occupation.

CONCLUSIONS

The combination of the patient's clinical history, physical, laboratory, and radiologic findings support the diagnosis of extrinsic allergic alveolitis from the enzyme contained in the cleaner.

Lung cancer in a nonsmoking underground uranium miner

Working in mines is associated with acute and chronic occupational disorders. Most of the uranium mining in the United States took place in the Four Corners region of the Southwest (Arizona, Colorado, New Mexico, and Utah) and on Native American lands. Although the uranium industry collapsed in the late 1980s, the industry employed several thousand individuals who continue to be at increased risk for developing lung cancers. We present the case of a 72-year-old Navajo male who worked for 17 years as an underground uranium miner and who developed lung cancer 22 years after leaving the industry. His total occupational exposure to radon progeny was estimated at 506 working level months. The miner was a life-long nonsmoker and had no other significant occupational or environmental exposures. On the chest X-ray taken at admission into the hospital, a right lower lung zone infiltrate was detected. The patient was treated for community-acquired pneumonia and developed respiratory failure requiring mechanical ventilation. Respiratory failure worsened and the patient died 19 days after presenting. On autopsy, a 2.5 cm squamous cell carcinoma of the right lung arising from the lower lobe bronchus, a right broncho-esophageal fistula, and a right lower lung abscess were found. Malignant respiratory disease in uranium miners may be from several occupational exposures; for example, radon decay products, silica, and possibly diesel exhaust are respiratory carcinogens that were commonly encountered. In response to a growing number of affected uranium miners, the Radiation Exposure Compensation Act (RECA) was passed by the U.S. Congress in 1990 to make partial restitution to individuals harmed by radiation exposure resulting from underground uranium mining and above-ground nuclear tests in Nevada.

Giant cell pneumonitis induced by cobalt

Cobalt alone and in combination with tungsten carbide known as hard metal is capable of causing lung damage. This may vary from development of pulmonary oedema to asthma and fibrosing alveolitis. We report a case of giant cell interstitial pneumonitis caused by exposure to cobalt dust which was not identified as the etiological agent initially and hence led to progression of the disease. The patient subsequently improved following cessation of exposure and treatment with oral corticosteriods, thereby stressing the importance of occupational history in all cases of interstitial pulmonary fibrosis.

Pulmonary CT findings in acute mercury vapour exposure

AIM

We describe the pulmonary computed tomography (CT) findings in acute mercury poisoning.

MATERIALS AND METHODS

Initial (n= 8) and follow-up (n= 6) chest CT examinations in eight patients exposed to mercury vapour while cutting pipes in a sulphuric acid plant were reviewed. Of the eight patients, two were asymptomatic and had normal CT results, two were asymptomatic but had abnormalities on CT, and four had both acute symptoms and positive CT results. The patients were all men whose ages ranged from 37 to 54 years (mean, 49 years).

RESULTS

Poorly defined nodules were present in five of six patients with positive CT findings, present alone in two patients or as part of a mixed pattern in three. They were random in distribution. Alveolar consolidation (n= 3) and areas of ground-glass opacity (n= 4) were observed and were more prominent in the most severely affected patients with the highest blood and urine level of mercury, predominantly in the upper and/or middle zone. These abnormal findings on CT resolved with (n= 1) or without (n= 5) steroid therapy. Pathological findings (n= 1) demonstrated acute interstitial changes predominantly with oedema.

CONCLUSION

We report CT findings in eight patients acutely exposed to mercury vapour. The pulmonary injury was reversible on CT in these cases. Hashimoto, M. (2001). Clinical Radiology56, 17-21.

[Radiological evidence of lung involvement in metal fume fever]

We report the case of a 32-year-old welder who developed a flu-like syndrome a few hours after founding zinc. The patient experienced fever, headache, muscle pain and dyspnea that resolved spontaneously with a few hours. The diagnosis of metal fume fever was retained. The chest x-ray evidenced bilateral diffuse infiltrative pulmonary lesions, rarely described in this syndrome. Metal fume fever is a likely diagnosis in exposed patients who develop fever with diffuse lung involvement.

[Bronchiolitis obliterans in a patient previously working as a printer in a textile factory]

We report the case of a 24-year-old man with a diagnosis of bronchiolitis obliterans, a rare clinical condition; the similarity to Ardystil syndrome was striking. Relevant occupational history included work in a textile air-brushing factory. Also noteworthy were lesions observed by CT scan in the form of cystic formations measuring less than 1 cm, a finding not previously described in the context of bronchiolitis obliterans. The patient improved immediately after starting corticoid treatment although scans failed to improve over several months of follow-up.

Cervical spine abnormalities in professional singers

A systematic X-ray study of the cervical spine of three populations of subjects (professional singers, beginning singers, and non-singers) who exhibited no vertebral column pathology or postural disorders provided evidence of abnormalities in the shape of the cervical spine in all of the professional singers studied. The disorders observed included hypolordosis, and more frequently, cervical rectitude or hypocyphosis without functional hindrance. The findings can be explained in terms of deformations undergone by the cervical spine after many years of intensive singing. The resulting functional postures are memorized and become an integral part of the singer's corporal schema. The considerable amount of anterior-posterior movement of the cervical spine in singing explains why lesions which prevent its mobility have an overall impact on the singer's voice, particularly in the upper pitch range.

'Cable-maker's clavicle': stress fracture of the medial clavicle

A 50-year-old man presented with a non-traumatic painful swelling over the medial clavicle. Radiographs showed a poorly defined fracture and the possibility of an underlying pathology was raised. Computed tomography suggested a stress fracture. This prompted a further, more detailed occupational history to be obtained from the patient, which revealed a hitherto undescribed cause of clavicular stress fracture and obviated the need for further imaging or biopsy.

Functional brain imaging in the assessment of multiple chemical sensitivities

The author provides a brief overview of single photon emission computed tomography in the assessment of multiple chemical sensitivities.

[Giant hydatid of the left lung]

A case of giant hydatid cyst of the left lung submitted to conservative surgery is reported. The postoperative period was complicated by the appearance of a bronchopleural fistula and a residual cavity. The complication was treated with targeted double lumen drainage which enabled pleuroclysis with saline solution and betadine. The closure of the fistula, the elision of the cavity and recovery were accomplished after 95 days. These results demonstrate that conservative surgery is possible even in the presence of giant lung hydatid cyst. Major resections constitute an extreme measure.

Asbestos-related benign pleural disease

Benign pleural disease is the commonest manifestation of asbestos exposure encountered by radiologists. Benign pleural thickening can appear as circumscribed parietal pleural plaques or as more diffuse thickening of the visceral pleura. Benign-asbestos induced pleural effusions are a significant and under-recognized manifestation of asbestos exposure with important sequelae, such as diffuse pleural thickening which may be associated with functional impairment and for which compensation may be sought. This review concentrates on the strengths and weaknesses of chest radiography and computed tomography for the detection and characterization of benign asbestos-related pleural disease and the relevance of imaging abnormalities to compensation and functional impairment.Peacock, C. (2000). Clinical Radiology55, 422-432.