Irregular Opacities Research Articles

Radiographic abnormalities among Finnish construction, shipyard and asbestos industry workers.

The prevalence of asbestos-related radiographic abnormalities was surveyed among Finnish construction, shipyard, and asbestos industry workers. The radiographic screening focused on active and retired workers who were under the age of 70 years and had been employed for at least 10 years in construction or for at least 1 year in shipyards or in the asbestos industry. In 1990-1992, 18,943 people participated in an X-ray examination of the lungs and an interview on work history and exposure. The criteria for a positive radiological finding were (i) small irregular lung opacities clearly consistent with interstitial pulmonary fibrosis (ILO 1/1 or higher), (ii) lung opacities indicating mild pulmonary fibrosis (ILO 1/0) with unilateral or bilateral pleural plaques, (iii) marked adhesions with or without thickening of the visceral pleura, or (iv) findings consistent with bilateral pleural plaques. Fulfilling the criteria were 4133 workers (22%) (22% from construction, 16% from shipyards, and 24% from the asbestos industry). The radiological findings included signs of pulmonary fibrosis (3%), changes in the visceral pleura (7%), bilateral plaques (17%), and unilateral plaques (10%). Occupational disease was diagnosed according to the Finnish insurance regulations for three-fourths of those referred for further examinations, 96% being abnormalities in the pleura and 4% being asbestosis. Exposure to asbestos dust has been common in ordinary construction work, and, consequently, radiographic abnormalities (mostly pleural) occur frequently among active and retired construction workers.

Asbestos exposure: a potential cause of retroperitoneal fibrosis.

The etiology of retroperitoneal fibrosis is unknown in 70% of the cases. The aim of our study was to examine the possible association between occupational asbestos exposure and retroperitoneal fibrosis; only two cases have been reported in the literature. We gathered all the cases of retroperitoneal fibrosis diagnosed in the Tampere University Hospital between 1987 and 1995. We examined their hospital records to evaluate the possible etiology of the disease. We also sent a structured questionnaire to all living patients (10/13) to obtain information on their asbestos exposure. The chest radiographs of the patients were re-read to evaluate possible changes resulting from asbestos exposure. We found 13 cases of idiopathic retroperitoneal fibrosis. Seven patients (all male) had been exposed to asbestos in the past. The chest radiographs of the four most-exposed patients showed characteristic asbestos-related abnormalities, including bilateral pleural plaques, round atelectasis and small irregular lung opacities. In our study, we found that asbestos exposure and asbestos-induced changes in the lung and pleura were common among male retroperitoneal fibrosis patients. We suggest that occupational exposure to asbestos may be an important etiological factor for retroperitoneal fibrosis.

Fibrosis of the lung and pleura and long-term exposure to wollastonite

The purpose of this study was to determine whether long-term exposure to wollastonite causes fibrosis of the lung and pleura in humans. Forty-nine workers (mean exposure 25 years) in a Finnish limestone-wollastonite mine and mill were examined. Their work histories and symptoms of chronic bronchitis were recorded. The chest radiographs were classified according to the classification of the International Labour Office (1980); a radiographic follow-up from 1981 to 1990 was included. Spirometry and diffusion capacity were measured. Four workers underwent high-resolution computed tomography (HRCT) and bronchoalveolar lavage (BAL). Lung tissue specimens were available for 2 workers. Mineral fibers and asbestos bodies were analyzed from the BAL fluid and lung tissue specimens, which were also analyzed for lung fibrosis. Two workers (4%) had small irregular lung opacities (ILO 1/0), 1 worker (2%) ILO 0/1 of the s/t type. HRCT revealed no parenchymal fibrosis in the 2 workers with the ILO 1/0 classification. Of the 9 workers (18%) with pleural plaques, 5 had been exposed to asbestos. Multivariate logistic regression analyses revealed no association of plaques with the duration of wollastonite or asbestos exposure. Wollastonite fibers or bodies were not found in any of the 4 workers who underwent BAL, nor in either of the workers whose lung tissue specimens were available. No evidence was found that long-term exposure to wollastonite causes parenchymal fibrosis of the lung and pleura. Furthermore, the findings indicate that wollastonite fibers are poorly retained in human lungs.

Relation of spirometric function to radiographic interstitial fibrosis in two large workforces exposed to asbestos: an evaluation of the ILO profusion score.

To analyse quantitatively the relations of spirometric lung function (forced vital capacity (FVC)) to radiographic interstitial pulmonary fibrosis (assessed by the International Labour Organisation (ILO) profusion score of small irregular opacities) in two large workforces exposed to different intensities of asbestos. These analyses consider the question whether a similar profusion score n differently exposed workers is associated with a similar effect on lung function. Surveys of two workforces, insulators (n = 2611) and sheet metal workers (n = 1245), by the same investigators allowed comparison of the effects of the two levels of exposure to asbestos. The two groups were of similar age and had similar percentages of non-smokers and smokers. All radiographs were read by the same expert reader. Consistent with their less continuous and less intense exposure to asbestos, metal workers had: (a) far less frequent radiographic asbestosis (profusion score > or = 1/0, 17.5% v 59.6% for insulators): (b) less severe radiographic asbestosis (only 1.1% had scores > or = 2/1 v 13.3% of insulators); (c) a similar slope to that seen in insulators for the relation between FVC and profusion score when pleural thickening was absent; (d) less frequent pleural fibrosis (36% v 75%); and (e) less frequent restrictive impairment (23% v 33%). In both insulators and metal workers, lung function was below normal even when lung fields were normal, FVG fell with increasing profusion, it was lower in smokers and in those with pleural thickening at comparable profusion scores, and these was no difference in FVC between scores 0/1 and 1/0. The decrease in FVC with increasing profusion score in both workforces as well as the similar slopes for the relation between FVG and profusion score and the similar FVG at similar scores in the absence of pleural thickening confirm the ILO profusion score as an acceptable assessment of pulmonary fibrosis.

The alphabet soup revisited: the chronic interstitial pneumonias in the 1990s.

Liebow classified the idiopathic interstitial pneumonias as usual (UIP), desquamative (DIP), bronchiolitis obliterans (BIP), lymphoid (LIP), and giant cell (GIP) interstitial pneumonias. This classification was modified to exclude LIP and GIP. UIP, the most common type, is characterized by synchronous foci of inflammation, collagen deposition, and fibrosis with interspersed normal lung. It usually affects men 40-60 years old and manifests radiologically with bilateral, basilar irregular opacities and volume loss. In most cases, a confident diagnosis can be made at high-resolution computed tomography because of characteristic subpleural irregular linear opacities, ground-glass opacities, honeycombing, and traction bronchiectasis. DIP affects younger patients and is characterized by diffuse intraalveolar macrophage aggregation. Typical radiologic features include bilateral, basilar ground-glass opacities and preserved lung volumes. BIP, renamed bronchiolitis obliterans with organizing pneumonia, affects middle-aged patients and manifests with multifocal plugs of immature fibroblasts in the air spaces. Typical radiologic features include bilateral consolidations and normal lung volumes. Recently described entities include acute (AIP) and nonspecific (NIP) interstitial pneumonias and respiratory bronchiolitis with interstitial lung disease (RB-ILD). AIP is a rapidly progressive, often fatal, illness characterized by diffuse alveolar damage and manifests with clinical and radiologic features of adult respiratory distress syndrome. NIP is a heterogeneous group of fibrosing disorders that cannot be otherwise classified. RB-ILD is a disease of smokers with a good prognosis.

Disease Progression in Usual Interstitial Pneumonia Compared With Desquamative Interstitial Pneumonia: Assessment With Serial CT

To determine the outcome of areas of ground-glass attenuation and assess disease progression on serial high-resolution CT (HRCT) scans of patients with biopsy specimen-proved usual interstitial pneumonia (UIP) and desquamative interstitial pneumonia (DIP). Twelve patients with biopsy specimen-proved UIP and 11 patients with biopsy specimen-proved DIP who had initial and follow-up HRCT scans (median interval, 10 months) were reviewed. Eleven patients with UIP and 11 with DIP received treatment between the initial and follow-up CT scans. The scans were evaluated for the presence and extent of ground-glass attenuation, irregular linear opacities and honeycombing, and overall extent of parenchymal involvement. On initial CT scans, all 12 patients with UIP had areas of ground-glass attenuation (mean +/- SD extent, 30 +/- 16%) and irregular lines (mean +/- SD extent, 17 +/- 7%) and 10 patients had honeycombing (mean +/- SD extent, 10 +/- 6%). All 11 patients with DIP had areas of ground-glass attenuation on initial HRCT scans (mean +/- SD extent, 51 +/- 26%), 5 patients had irregular linear opacities (mean +/- SD extent, 5 +/- 5%), and 1 patient had honeycombing. Nine of the 12 patients with UIP showed increase in the extent of ground-glass attenuation (n = 6) or progression to irregular lines (n = 2) or honeycombing (n = 4) on follow-up as compared with only 2 patients with DIP who showed progression to irregular lines (n = 1) or honeycombing (n = 1) (p < 0.01 chi 2 test). In patients with UIP, areas of ground-glass attenuation usually increase in extent or progress to fibrosis despite treatment. Areas of ground-glass attenuation in most patients with DIP remain stable or improve with treatment.

Serum KL-6 for the Evaluation of Active Pneumonitis in Pulmonary Sarcoidosis

KL-6, a mucinous high-molecular weight glycoprotein, expressed on type II pneumonocytes, is elevated in the serum of patients with active interstitial pneumonia. Forty-seven patients with histologically confirmed sarcoidosis were analyzed by chest radiography, CT, 67Ga scintigraphy, BAL fluid (BALF), and serum KL-6. Serum KL-6 level was significantly elevated in radiographic type II (945 +/- 725 U/mL; n = 13; p < 0.01) and type III (1,179 +/- 1,320 U/mL; n = 9; p < 0.01), as compared with type 0 (333 +/- 173 U/mL; n = 10) and type I (430 +/- 225 U/mL; n = 15). Serum KL-6 level was significantly elevated in patients with CT findings of irregular small opacities, ground-glass opacities, and thickened bronchovascular bundle (p < 0.01), as compared to those without these findings. Serum KL-6 level was significantly elevated in patients with positive pulmonary accumulation in 67Ga scintigraphy (1,108 +/- 1,044; n = 20; p < 0.001) as compared to those without accumulation (390 +/- 206; n = 27). Serum KL-6 level was elevated in patients with a higher CD4+/CD8+ ratio (> or =3) in BALF, as compared to those with lower ratios. These results suggest that serum KL-6 is a useful marker of sarcoidosis activity.

Respiratory health in asbestos-exposed ironworkers

This study aimed to determine the prevalence of respiratory morbidity among asbestos-exposed ironworkers and to determine the relationship between respiratory morbidity indices and length of exposure. A medical screening provided information on chest radiographic abnormalities, pulmonary function, rales, finger clubbing, and respiratory symptoms for 547 asbestos-exposed ironworkers. Union pension records furnished data on length of exposure. The study group exhibited on increased prevalence of small irregular opacities, pleural plaques, and pleural thickening on chest x-ray; reduced FEF 25-75; rales; and respiratory symptoms. After controlling for the effect of cigarette smoking and age, years since joining the ironworkers union were significantly associated with profusion, pleural thickening, pleural plaques, rales, percent predicted FVC, reduced FVC, reduced FEV1, reduced FEV1/FVC, and dyspnea grades I, II, III, and IV.

Breast Hamartoma With Invasive Ductal Carcinoma Report of Two Cases and Review of the Literature

Two cases of well-defined masses also containing clinical and radiographical abnormalities suggestive of malignancy, subsequently found to be invasive ductal carcinomas in breast hamartomas are described. The patients were 53 and 78 years old. Both presented with a generally soft palpable breast lump, containing a firm area which in one case invaded and ulcerated the skin. Mammography demonstrated two typical hamartomas: one containing a spiculated opacity, the other irregular opacities with suspicious calcifications, suggesting the presence of carcinomas in these benign lesions. The cut surface of these well-circumscribed masses measured 5 cm and 7 cm. The microscopic appearance was characteristic of breast hamartoma (sharp circumscribed "pseudocapsule" surrounding breast fibrocystic changes with variable amounts of adipose tissue) with the firm area in each case corresponding to invasive ductal carcinoma. In one case the invasive ductal carcinoma was confined to the hamartoma, whereas in the other malignant tumor, cells extended beyond the surrounding breast tissue and infiltrated the skin. These findings raise the question of secondary involvement of a hamartoma by invasive carcinoma. Breast hamartomas are probably underrecognized lesions. In our view, these findings do not justify a more aggressive approach towards the management of breast hamartomas.

Ocular and Systemic Manifestations of Cerebrotendinous Xanthomatosis

Cerebrotendinous xanthomatosis is a storage disease that usually leads to severe mental and neurologic deterioration before the diagnosis and start of treatment are established. We identified major ocular and systemic characteristics that may enable a diagnosis to be made earlier. Ten patients (group 1) of the University Hospital Nijmegen, with a diagnosis of cerebrotendinous xanthomatosis, were re-examined for detailed ocular and major clinical manifestations. Meanwhile, we looked for similar but undiagnosed cases in patients (group 2) who visited the Institute of Ophthalmology during a 12-month period. A diagnosis of cerebrotendinous xanthomatosis had been made in the patients of group 1 at an average age of 40 years (range, 33 to 48 years). Subsequently, six new cases (group 2) were diagnosed in patients 7 to 37 years old (average age, 18 years). Bilateral cataract was the major ocular manifestation in all 16 patients. Small irregular corticonuclear opacities, anterior polar cataracts, and dense posterior subcapsular cataracts were diagnosed at various ages (mean, 18 years; range, 4 to 40 years). Four patients showed clinical signs of optic neuropathy, whereas retinal function was normal in all patients. Other major clinical signs included a history of chronic diarrhea (since childhood), mental deterioration (mean age, 23 years), neurologic deterioration (mean age, 31 years), and tendon xanthomas (mean age, 37 years). Appropriate biochemical investigations for cerebrotendinous xanthomatosis should be performed in patients with unexplained juvenile or early-onset adult cataracts, especially if these cataracts are associated with chronic diarrhea since infancy, mental retardation or deterioration, neurologic dysfunction, or xanthomas.

Airways Obstruction From Asbestos Exposure and Asbestosis Revisited

obstruction (reduced FEF25-75 and FEF75-85) as shown in 8,720 asbestos-exposed workers who at various times during this evolution show irregular opacities as seen in the chest x-ray films.1 Thus, the disease's functional signs precede the radiographic manifestations. This was confirmed pathologically as fibrosis was found far more often on tissue sections when lung was examined from asbestos workers with lung cancer.2 These studies since have been replicated in over 8,000 additional workers. We studied,

Airways Obstruction From Asbestos Exposure

To define the apparent steps in developing airways obstruction vs restrictive lung disease in men exposed to asbestos for more than 20 years who had never smoked vs cigarette smokers.Physiologic signs of asbestosis were studied in cross-sectional age-matched groups of never, current, and ex-cigarette smoking workers.The study included 8,720 asbestos-exposed construction and shipyard workers in the United States.FVC, FEV1, FEF25-75, and FEF75-85 were measured by spirometry and total lung capacity (TLC) by planimetry of standard chest radiographs and adjusted for height, age, and duration of cigarette smoking and expressed as percentage of predicted. TLC minus FVC yielded RV. We compared means and mean residuals (measurement minus group mean) expiratory flows and lung volumes in 1,146 men with pulmonary asbestosis age matched to 1,146 without asbestosis who had similar durations of asbestos exposure and to 370 men without asbestos exposure. Next, flows and volumes were regressed against the International Labour Office (ILO) profusion scale of irregular opacities on chest radiographs (PIO) and the duration of asbestos exposure for 1,777 never smokers (NS), 4,550 current smokers, and 2,393 ex-smokers.Asbestos exposure in NS men decreased expiratory flows and increased TLCs compared with unexposed NS men. Further reductions in flows and FVC and increases RV/TLC with radiographic asbestosis were not statistically significant. As the PIO increased from 1/1 to 3/3, obstruction and air trapping increased significantly but TLC did not.Asbestos exposure reduced flows and produced air trapping after 20 years in workers who never smoked. Smoking increased these abnormalities.

Non-palpable lesions of the breast detected by mammography — Review of 1182 consecutive histologically confirmed cases

We report on 1182 consecutive histologically confirmed non-palpable breast lesions detected by mammography (infiltrating carcinoma 427, in situ carcinoma 121, benign 634). The proportion of cancer cases varied according to age (< 50 years = 33%; 50-59 years = 46%; > 59 years = 63%), mammographic pattern (regular opacities = 8%, parenchymal distortions = 20%, isolated calcifications = 42%, irregular opacities = 62%, stellate opacities = 73%), and calendar period (1970-1985 = 29%, 1986-1989 = 56%; 1990-1992 = 69%). A sharp decrease of the benign/malignant biopsy ratio was evident after routine fine-needle aspiration cytology (sonography-guided or stereotaxic) was introduced in 1986. The independent significant association of cancer frequency to age, calendar period and mammographic pattern was confirmed by multivariate analysis. A significant trend over time in favour of conservative surgery was also observed for cancer cases (1970-1979 = 6%, 1980-1985 = 41%, 1986-1992 = 83%). Among invasive cancers, node involvement was observed in 11.5% of cases, being associated with tumour size (pT1a = 0%, pT1b = 7%, pT1c = 13%, pT2a = 33%). Five-, ten- and fifteen-year overall survivals of invasive cancers were 98.1, 95.7 and 87.3%, respectively.

Recognition and progression of coal workers' pneumoconiosis in the collieries of northern France.

In France, both active and retired coal miners take part in medical surveillance programs. Those compensated for pneumoconiosis are registered and receive annual chest X-rays and regular lung function assessments. A longitudinal study was done among 2719 pneumoconiotics from the Nord-Pas de Calais region Compensation Register, who received first compensation between 1942 and 1987 to study progression of CSWP. Chest radiographs taken at time of compensation and in 1987 were examined by three independent readers. There was a change over time in the characteristics of pneumoconiosis at the time of first compensation toward a low profusion of irregular opacities. In the period from 1982 to 1987, 645 pneumoconiotics developed progressive massive fibrosis (PMF). The occurrence of PMF was related to the date of compensation and the profusion of small opacities at detection (after controlling for time to follow-up). Two profiles for changes in coal workers' simple pneumoconiosis (CWSP) were observed: the first in the group of subjects with mild pneumoconiosis at compensation, who did not reach category 2 at follow-up and had a low attack rate of PMF; and the second in the group of those compensated for category 1/2 pneumoconiosis or higher, who reached severe CWSP and had a twofold attack rate for PMF at follow-up. The changes observed in the characteristics of pneumoconiosis at first compensation between 1942 and 1987 suggest a lessening of disease severity.

Epidemiology of Pneumoconiosis in Coalminers of Nord-Pas de Calais in France

This was a longitudinal study of 3167 active or retired pneumoconiotic coalminers from Nord-Pas de Calais collieries (HBNPC, acronym in French) recognized through medico-legal decisions over three delined periods: 1942-1961, 1962-1981 and 1982-1987. Periodic medical examinations of pneumoconiotics are provided by the medical services of HBNPC for miners and exminers. Physicians involved in this follow-up programme are concerned with the high incidence of progressive massive fibrosis (PMF). The objectives of this study were to describe pneumoconiosis at time of compensation and examine factors related to the occurrence of PMF. For each subject, two radiological films were extracted from the medical files. They were reinterpreted according to the ILO classification (ILO, 1980) by three independent medical readers. Results indicated that radiological criteria for compensation had changed over time ; a marked predominice of category 212 small opacities was noted for cases compensated before 1962 and a predominice of category 1/1 among those compensated after 1981. Comparison of distribution of small opacity types in the 1942-1961 period with that in 1982-1987 confirmed the progressive fall, reported by other investigators, of proportions of predominant micronodular opacities accompanied by an increase in proportions of small irregular opacities at compensation [COCKCROFT and ANDERSON, Br. J. ind. Med. 44,484-487 (1987)]. When time interval between films was taken into account, profusion of small opacities at compensation greater than 1/1 was associated with a probability of 40% or more of developing PMF. Severity of coalworkers simple pneumoconiosis (CWSP) at compensation in HBNPC has been seen to decline since 1982 and the disease to occur mostly after retirement. The reported changes in small opacity types suggest a reduction in incidence of pure silicosis. Occurrence of PMF was correlated with profusion of small opacities at compensation.

RESPIRATORY BRONCHIOLITIS-ASSOCIATED INTERSTITIAL LUNG DISEASE

Respiratory bronchiolitis-associated interstitial lung disease is a distinct clinical syndrome found in current or former cigarette smokers. The disease often is confused with other interstitial lung diseases, especially idiopathic pulmonary fibrosis. The clinical presentation resembles those of patients with other interstitial lung diseases--cough and dyspnea, with coarse rales on physical examination. Diffuse fine reticulonodular interstitial opacities are found on chest radiograph, usually with normal-appearing lung volumes. Bronchial wall thickening, prominence of peribronchovascular interstitium, small regular and irregular opacities, and small peripheral ring shadows are distinctive features. Pulmonary function testing may be normal but usually demonstrates mild to moderate restriction and normal or slightly reduced diffusing capacity. A mixed obstructive-restrictive pattern is common. Respiratory bronchiolitis-associated interstitial lung disease is characterized histologically by an inflammatory process involving the membranous and respiratory bronchioles. The pathologic findings are dominated by the finding of tan-brown pigmented macrophages within respiratory bronchioles and neighboring alveolar ducts and alveoli. The pulmonary parenchyma away from the airway usually is normal or may demonstrate mild hyperinflation. The clinical course and prognosis of respiratory bronchiolitis-associated interstitial lung disease are unknown. Most patients respond favorably to corticosteroids, with documented improvement in lung function and chest radiographs. Smoking appears to play a role in the pathogenesis, so smoking cessation is important in the resolution of this syndrome.

Computed tomography in the early detection of asbestosis.

Computed tomography (CT; both conventional (CCT) and high resolution (HRCT)) scans of the thorax were evaluated to detect early asbestosis in 61 subjects exposed to asbestos dust in Québec for an average of 22(3) years and in five controls. The study was limited to consecutive cases with chest radiographs of the International Labour Organisation categories 0 or 1 determined independently. All subjects had a standard high kilovoltage posteroanterior and lateral chest radiograph, a set of 10-15 1 cm collimation CCT scans and a set of three to five 2 mm collimation HRCT scans in the upper, middle, and lower lung fields. Five experienced readers independently read each chest radiograph and sets of CT scans. On the basis of three to five readers agreeing for small opacities of the lung parenchyma, 12/46 (26%) negative chest radiographs were positive on CT scans, but 6/18 (33%) positive chest radiographs were negative on CT scan. On the basis of four to five readers agreeing on a chest radiograph, 36/66 (54%) subjects were normal (group A), 17/66 (26%) were indeterminate (group B), and 13/66 (20%) were abnormal (group C). By the combined readings of CCT and HRCT, 4/31 (13%) asbestos exposed subjects of group A were abnormal (p < 0.001), 6/17 (35%) of group B were abnormal, and in group C, 1/13 (8%) was normal, 2/13 were indeterminate, and 10/13 (77%) were abnormal. Separate readings of CCT and HRCT on distinct films in 14 subjects showed that all cases of asbestosis were abnormal on both CCT and HRCT. Inter-reader analyses by kappa statistics showed significantly better agreement for the readings of CT than the chest radiographs (p < 0.001), and for the reading of CCT than HRCT (p < 0.01). Thus CT scans of the thorax identifies significantly more irregular opacities consistent with the diagnosis of asbestosis than the chest radiograph (20 cases on CT scans v 13 on chest radiographs when four to five readers agreed, 13% of asbestos exposed subjects with normal chest radiographs or 21% of asbestos exposed subjects with normal or near normal chest radiographs. It decreased the number of indeterminate cases significantly from 17 on chest radiographs to 13 on CT scans. All cases of asbestosis detected only on CT scans were similarly seen on CCT and HRCT and did not have significant changes in lung function. The CT scans significantly reduced the inter-reader variability, despite the absence of ILO type reference films for these scans.

Prevalence of small opacities in chest radiographs of nickel sinter plant workers.

Radiographs from 745 nickel sinter plant workers were taken and classified by five readers using the International Labour Office (1980) protocol. Each reader worked independently and the films were randomly mixed with films from a non-dust exposed office population and also with films from subjects known to have silicosis or asbestosis. The prevalence of small irregular opacities was selected as the outcome of interest. In the sinter workers this was within the range identified in cigarette smokers or in workers exposed to dusts of low fibrogenicity. Only minimal evidence of small round opacities was noted. There was no evidence from the chest radiographs that exposures to high concentrations of dusts containing compounds of nickel caused an inflammatory or fibrogenic response in the lungs of the exposed population.

Acute pulmonary complications in immunocompromised non-AIDS patients: Comparison of diagnostic accuracy of CT and chest radiography

To compare the abilities of computed tomography (CT) and radiography in detection and diagnosis of acute pulmonary complications in immunocompromised non-AIDS patients, the CT scans and radiographs of 45 immunocompromised non-AIDS patients with proven pulmonary disease and 20 normal controls were independently assessed by two observers, without knowledge of clinical or pathologic data. The observers listed the three most likely diagnoses and their degree of confidence in the first-choice diagnosis on a three-point scale. The sensitivity and specificity in detecting pulmonary complications was 100% and 98% for CT, compared to 98% and 93%, respectively, for chest radiography. In the immunocompromised patients, the first-choice diagnosis was correct in 44% of CT and 30% of radiograph readings (P < 0.01). The correct diagnosis was among the top three diagnoses in 70% of CT scans and 53% of radiograph readings (P < 0.01). Confidence level one (definite) was reached in 33% of CT scans and 10% of chest radiographs (P < 0.001). Diseases with a dominant nodular pattern had a higher occurrence of correct first-choice diagnosis (62% vs 34%, P < 0.02) and level one confidence ratings (53% vs 13%, P < 0.001) than diseases with ground-glass opacity, consolidation or irregular linear opacities. We conclude that chest radiographs and CT scans have comparable sensitivity in detecting acute pulmonary complications in immunocompromised non-AIDS patients. CT is superior to chest radiography in the differential diagnosis of acute pulmonary complications in these patients.

Total Lung Capacity in Asbestosis: A Comparison of Radiographic and Body Plethysmographic Methods

The effect of asbestosis on lung volumes was studied in 46 workers by measuring total lung capacity (TLC), forced vital capacity, vital capacity, and residual volume using two standard methods: body plethysmography and radiographic lung area. Nine men had neither irregular opacities of any International Labour Office profusion category nor pleural abnormalities; 9 had pleural abnormalities only, 19 had irregular opacities only; and 9 had pulmonary asbestosis with pleural plagues. Of the 28 with irregular opacities, 18 had moderate or advanced asbestosis (category 2/1 or greater). The radiographic method gave a mean TLC of 8.11 L and the body plethysmographic mean was 8.09 L. Thus, the radiographic and plethysmographic methods produced virtually identical mean values for TLC and for residual volume 3.84 L and 3.8 L and residual volume/TLC, 47.3 and 47.3, respectively. Lung volumes measured by body plethysmography and by x-ray area were the same in each of the four radiographic categories of asbestosis. The air trapping and normal or slightly elevated TLC, which characterize asbestosis in men who have smoked cigarettes, are revealed by both methods. The radiographic method, when adequate measures are taken to obtain full inspirations, effectively duplicates the body plethysmographic method but is quicker and simpler, particularly for field studies.