Occupational lung disease radiology imaging-mahesh.pptx

radiology imaging of human body in occupational lung diseases in proper seminar formats

1. IMAGING IN OCCUPATIONAL LUNG DISEASE Moderator - Dr Mohan Presenter - Dr Javin Justin

2. INTRODUCTION Occupational lung disease comprises a wide variety of disorders caused by the inhalation or ingestion of dust particles or noxious chemicals. These disorders include : P neumoconiosis , A sbestos-related pleural and parenchymal disease, C hemical pneumonitis , Occupational infection, Hypersensitivity pneumonitis , and O rganic dust toxic syndrome

3. Occupational lung disease represents the 2 nd most frequently diagnosed work-related condition The development of occupational lung disease is dependent on : -the toxic effects of the inhaled substance, Intensity. Duration of the exposure. The physiologic and biologic susceptibility of the host.

4. Pneumoconiosis Pneumoconiosis is a tissue reaction to the presence of an accumulation of dust in the lungs . Presents in two forms: One is fibrosis : - focal ( as in silicosis) - diffuse (as in asbestosis ). It often results in radiographic abnormalities The other form consists of aggregates of particle laden macrophages with no accompanying fibrosis. seen with inert dusts such as iron, tin, and barium . It usually results in few, functional or clinical manifestations

5. Silicosis and Coal Worker Pneumoconiosis Though differing histologic Features, the radiographic and HRCT appearances of silicosis and CWP are quite similar, so that the two disease entities cannot be easily or reliably distinguished in individual cases

6. The principal sources of industrial exposure to silica are: - free silica in mining, -quarrying, and -tunneling; -stonecutting, -polishing, and - cleaning monumental masonry; -sandblasting and -glass manufacturing; Coal miners are exposed to dusts that contain a mixture of coal, mica, kaolin, and silica in varying proportions

7. Imaging Features The characteristic radiologic abnormality seen in patients with simple silicosis or CWP consists of small , well-circumscribed nodules that are usually 2–5 mm in diameter but range from 1 to 10 mm, mainly involving the upper and posterior lung zones Small nodules indicate the presence of simple or uncomplicated silicosis or CWP

8. Complicated silicosis or complicated CWP. : indicated by The appearance of large opacities or hyperattenuating areas over 1 cm in diameter ( progressive massive fibrosis ) These masses tend to develop in the midzone or periphery of the upper lung. Tend to migrate toward the hila , leaving overinflated emphysematous spaces between the conglomerate mass and the pleura. They are often bilateral, symmetric, and calcified and can demonstrate cavitations. Egg-shell calcifications in hilar and mediastinal lymph nodes are occasionally seen

9. Simple silicosis in a 59-year-old man who worked in hard-rock mining for 10 years . Chest radiograph shows diffuse nodular opacities with relative sparing of the basal lung zones.

10. Highresolution CT scan shows numerous micronodules in both upper lungs with posterior zonal predominance. Nodules are more profuse in the right upper lung zone than in the left. Some nodules are centrilobular in location (arrows). (2) CWP in a 48-yearold man . High-resolution CT scan shows numerous small nodules that are less well defined than those seen in silicosis.

11. Complicated CWP in a 57-year-old man. (a) Chest radiograph shows a conglomeration of small nodules with sparing of the bibasilar area and egg-shell calcifications in both hila . (b) High-resolution CT scan shows conglomerate masses (progressive massive fibrosis) and adjacent small nodules. A thoracostomy tube (arrowhead) was placed in the left hemithorax for a pneumothora x

12. Calcified progressive massive fibrosis in a 60-year-old retired coal worker. High-resolution CT scan ( mediastinal windowing) shows a densely calcified right parahilar mass. Complicated silicosis in a 58-yearold man . High-resolution CT scan shows a cavitary conglomerate mass in the left upper lobe.

13. Dust Deposition and Lymphatic Clearance: Radiologic Perspective The main driving force for lymphatic flow is pulmonary arterial pressure. Because the main pulmonary artery is inclined to the left, higher blood flow and lymphatic flow occur in the left upper lobe than in the right. The outward movement of the lateral chest wall is more than that of the posterior chest wall. These Regional differences in lymphatic flow result in poor clearance of particles from the posterior part of the right upper lung zone. This results in superoposterior predilection for dust retention

14. Acute Silicosis Acute silicosis , also known as silicoproteinosis , is a rare condition related to heavy exposure to respirable free silica in enclosed spaces Exposure times are frequently as short as 6–8 months . The disease is often rapidly progressive, with death caused by respiratory failure.

15. Imaging features are similar to those of pulmonary alveolar proteinosis Chest radiographs demonstrate a pattern of diffuse airspace or ground-glass disease in a perihilar distribution with air bronchograms Tuberculosis and infection with atypical mycobacteria are frequent complications.

16. Silicoproteinosis in a 52-year-old quarry worker . High-resolution CT scan of the right lung shows patchy areas of ground-glass attenuation with fine intralobular reticulation (“crazy paving” pattern) (arrowheads ), findings that are common in alveolar proteinosis . Bronchoalveolar lavage and transbronchial lung biopsy confirmed the presence of alveolar proteinosis and silica particles.

17. Siderosis Results from exposure to iron oxide in fumes during the welding process. The majority of cases of siderosis are seen in electric arc or oxyacetylene torch workers Siderosis is believed to be unassociated with fibrosis or functional impairment . however, When the iron is admixed with a substantial quantity of silica, the resulting silicosiderosis ( mixed-dust pneumoconiosis ) can lead to appreciable pulmonary fibrosis and disability

18. The radiographic pattern in pure siderosis consists of diffuse fine reticulonodular opacities . In contrast to the majority of cases of pneumoconiosis, the radiographic abnormalities can partially or completely disappear when patients are removed from dust exposure. High-resolution CT findings include : widespread , poorly defined centrilobular micronodules branching linear structures or extensive ground-glass attenuation without zonal predominance and fibrosis

19. Arc welder pneumoconiosis in a 46-year-old nonsmoker with a 15-year history of employment as a shipyard welder. High-resolution CT scan shows numerous small nodules and branching areas of hyperattenuation that are poorly defined and centrilobular . The diagnosis of siderosis was proved at transbronchial lung biopsy . .

20. Arc welder pneumoconiosis in a 57-year-old former smoker with a 13-year history of work in shipyards. The patient was asymptomatic, and the results of pulmonary function tests were normal. High-resolution CT scan shows groundglass attenuation that is diffuse and mainly centrilobular . Follow-up high-resolution CT performed 1 year later showed no change in the parenchymal disease

21. Asbestos-related Pleural and Parenchymal Disease Exposure to asbestos is an important public health hazard in all industrial societies Asbestos can be classified into two large groups: serpentines and amphiboles. Chrysotile- accounts for more than 90% of the asbestos used - belongs to serpentine group

22. Clinical manifestations typically do not appear until 20 years after initial exposure The inhaled asbestos fibre is long (up to 100micrometer in length), penetrates deeply into the lung and pleura, and has a fibrogenic effect on respiratory bronchioles , alveoli, and pleura.

23. Asbestos-related diseases include B enign pleural diseases - plaques , -diffuse pleural thickening , -effusion, -calcification P arenchymal diseases -asbestosis[ parenchymal fibrosis caused by asbestos inhalation ] -rounded atelectasis M alignancy -malignant mesothelioma . - bronchogenic carcinoma.

24. Asbestos-related Benign Pleural Disease Pleural plaques are the most common manifestation of asbestos exposure . are not usually associated with symptoms or functional impairment.

25. Discrete, focal irregular areas of pleural thickening that generally affect the parietal pleura Noted along the posterolateral and diaphragmatic contours of the lower thorax sparing of the lung apices and costophrenic Angles Asbestosis rarely occurs in the absence of pleural plaques

26. pleural effusion : The development of a pleural effusion is probably the earliest manifestation of previous asbestos exposure, usually occurs within 10 years of exposure ,

27. Diffuse pleural thickening is seen less frequently than pleural plaques is defined as a smooth, uninterrupted pleural density extending over atleast one fourth of the chest wall, with or without costophrenic angle obliteration Diffuse pleural thickening is less specific to asbestos exposure than are pleural plaques , Unlike pleural plaques, diffuse pleural thickening is frequently associated with functional impairment

28. Pleural plaques, diffuse pleural thickening, rounded atelectasis , and asbestosis in a 50-year-old man with asbestos exposure from working in a brake lining production plant. (a) Chest radiograph shows diffuse thickening of the left pleura and curvilinear band opacities in the left lower lung zone

29. High-resolution CT scan (lung windowing) obtained at the level of the liver dome shows a visceral pleural plaque in the right major fissure (arrow ). Note also the rounded atelectasis with posterior displacement of the left major fissure. The diagnosis of asbestosis was proved at open lung biopsy

30. High-resolution CT scan ( mediastinal windowing ) shows pleural plaques on the right side (small white arrows) and rounded atelectasis (large white arrow ) with adjacent diffuse pleural thickening (black arrows) on the left sid e.

31. High-resolution CT scan demonstrates pleural plaques along the diaphragmatic contour (black arrows) and an irregular attenuation pattern, which is typical in rounded atelectasis (white arrows).

32. Asbestosis It is Parenchymal fibrosis caused by asbestos inhalation There is a definite dose-effect relationship. Disease usually occurs approximately 20 years following initial exposure .

33. Parenchymal fibrosis begins in and around the respiratory bronchioles in the lower lobes adjacent to the visceral pleura where asbestos fibers tend to accumulate . This stage may progress to diffuse interstitial fibrosis and “honeycombing,” with complete destruction of the alveolar architecture

34. Radiologic changes consist of small, irregular opacities or hyperattenuating areas in a linear pattern. The fine reticulation eventually progresses to a coarse linear pattern with honeycombing. These abnormalities are usually most severe in the lower lungs, the posterior lungs, and in a subpleural location . These findings are similar to those in idiopathic pulmonary fibrosis. The presence of pleural plaques lends support to the radiologic diagnosis of asbestosis.

35. Major CT findings in early asbestosis include thickened intralobular lines , thickened interlobular lines, subpleural curvilinear lines, pleura-based nodular irregularities,patchy areas of ground-glass attenuation, small cystic spaces, and small areas of hypoattenuation

36. Asbestosis in a 62-year-old man. Prone high-resolution CT scan shows bilateral subpleural reticular hyperattenuating areas, small cysts. Video-assisted thoracoscopic surgical biopsy revealed asbestosis and discrete pleural plaques.

37. Rounded Atelectasis The most common of the benign masses caused by asbestosis exposure is rounded atelectasis , a form of peripheral lobar collapse It usually occurs in the subpleural , posterior, or basal region of the lower lobes . pleural thickening is always present and is frequently greatest near the mass

38. The mass often has a curvilinear tail , frequently referred to as the “ comet tail sign .” This sign is produced by the crowding together of bronchi and blood vessels that extend from the lower border of the mass to the hilum

39. Irregular masses are visible bilaterally in the anterior lung. B: A tissue window scan shows that these opacities are adjacent to areas of pleural thickening (arrows). C: CT obtained with 5-mm slice thickness better shows the comet-tail sign (arrow) of rounded atelectasis

40. .. D: Lung slice in a patient with asbestos exposure and rounded atelectasis . Visceral pleural fibrosis is associated with invagination of the pleura (black arrows). The major fissure and a large vessel (white arrows) bow toward the region of atelectasis (i.e., the comet-tail sign is present).

41. Bronchogenic Carcinoma and Asbestos Exposure Bronchogenic carcinoma is estimated to develop in 20%–25% of workers who are heavily exposed to asbestos. smoking and asbestos exposure interact in a multiplicative manner . the risk being 80–100 times that in the nonsmoking, nonexposed population

42. Asbestos-related tumors frequently occur in the periphery of the lungs with a lower lobe distribution, which correlates with the usual distribution of asbestosis

43. Malignant Mesothelioma Fatal neoplasm of the serosal lining of the pleural cavity, peritoneum, or both. The risk of mesothelioma in an asbestos worker is approximately 10 % over his or her lifetime Persons at risk include not only the worker but other household members as well as persons who reside near asbestos mines and plants Usually, a latency period of approximately 20–40 years occurs between exposure and tumor detection.

44. The tumor commences as nodules on the visceral or parietal pleura that progress to a thick rind encasing and constricting the lung Unilateral pleural effusion is the most frequent initial chest radiography finding. At CT, the combination of: - Mediastinal pleural involvement and - Thick (1 cm), nodular, circumferential pleural thickening - is highly suggestive of diffuse mesothelioma

45. Malignant mesothelioma in a 51-year-old man . (a) Chest radiograph shows irregular nodular pleural thickening in the right hemithorax

46. (b) Intravenous contrast- enhanced CT scan helps confirm an irregular thick rind along the right pleural surface. (c) CT scan shows tumor invasion of the abdomen (arrow).

47. Hypersensitivity Pneumonitis Hypersensitivity pneumonitis , an immunologic occupational lung disease Both type III and type IV immune reactions play a role in the pathologic response in the lung The particulate organism or protein complex that causes hypersensitivity pneumonitis is small, typically 1–2 micrometer and always less than 5micrometer in diameter

48. Chest radiographic findings include -a normal pattern , - miliary nodulation , - ground-glass opacity in both lungs. Hypersensitivity pneumonitis may be the most common diffuse lung disease exhibiting normal radiographic findings

49. HRCT findings Acute hypersensitivity pneumonitis - Typically consist of diffuse airspace consolidation . S ubacute hypersensitivity pneumonitis - consist of patchy or diffuse areas of ground-glass attenuation -small, centrilobular nodular areas of hyperattenuation

50. Chronic hypersensitivity pneumonitis is characterized by the presence of fibrosis which include : - intralobular interstitial thickening, -irregular interfaces, -irregular interlobular septal thickening, - honeycombing, and -traction bronchiectasis . usually involves mainly the middle or lower lung zones Relative sparing of the lung bases usually allows distinction of this entity from idiopathic pulmonary fibrosis , in which the fibrosis usually predominates in the lung bases

51. Chest radiograph shows patchy airspace consolidation throughout both lungs. A predominantly peripheral area of consolidation is seen in the right lung .

52. High-resolution CT scan obtained on the 2nd day of hospitalization shows patchy areas of consolidation and ground-glass attenuation in both lungs and less profuse small nodular hyperattenuating areas. Follow-up high-resolution CT performed 9 days later showed complete resolution of the parenchymal hyperattenuating areas .

53. Isocyanate -induced subacute hypersensitivity pneumonitis in a 36-year-old man who had been working as a painter .High-resolution CT scan shows patchy areas of ground-glass attenuation and small, predominantly centrilobular nodular hyperattenuating areas throughout both lungs

54. Byssinosis occurs in textile workers exposed to the dust of cotton, flax, hemp, and jute. In early stages, it characterstically presents with acute dyspnea , cough, and wheeze following a weekend away from the workplace. symptoms decrease during the work week Although the pathogenesis of byssinosis is unclear, it may be related to the presence of a bacterial endotoxin rather than the textile itself.

55. The imaging findings : have been sparsely described; however, basal predominant ground-glass opacities with associated centrilobular nodules have been reported on HRCT

56. Byssinosis in a 56-year-old woman who had had frequent episodes of “Monday fever” and dyspnea while working in a cotton quilt factory over a 7-year period. (a) Chest radiograph shows diffuse, ill-defined haziness predominantly in the lower lung zones.

57. High-resolution CT scan shows numerous ill-defined small nodules with ground-glass attenuation in both lungs. High-resolution CT scan obtained 23 days later shows resolution of the ground-glass attenuation with fewer residual small nodules than were previously noted. No abnormality was seen at high-resolution CT performed 1 year after the patient quit her job. In spite of prolonged exposure, the patient’s respiratory symptoms and pulmonary functional impairment resolved completely .

58. Conclusion Occupational lung disease is a diverse group of preventable pulmonary diseases. The characteristic radiological features suggest the correct diagnosis in some, whereas a combination of clinical features, occupational history , and radiological findings is essential in establishing the diagnosis in others.

59. HRCT is useful to make a specific diagnosis or limit the differential diagnosis. It plays a critical role in assessing disease activity. the presence of ground glass opacity and nodules suggest active disease which may be reversible on cessation of exposure , whereas presence of fibrosis is a marker of disease irreversibility.

60. References Imaging of Occupational Lung Disease- Kun-Il Kim, MD, Chang Won Kim- RadioGraphics Spectrum of high-resolution computed tomography imaging in occupational lung disease by Bhawna Satija , Sanyal Kumar - Indian Journal of Radiology and Imaging Uncommon Occupational Lung Diseases: High-Resolution CT Finding s- Lucía Flors1 Maria L. Domingo1 Carlos Leiva-Salinas1 - American Journal of Roentgenology

61. Thank you ….