Asbestosis is a chronic, progressive lung disease caused by inhalation of asbestos fibers. It typically develops 20-30 years after significant exposure. The diagnostic criteria include a history of asbestos exposure, appropriate time since exposure, radiographic evidence of opacities in the lung bases, restrictive lung impairment on pulmonary function tests, and crackles in the lung bases. Chest x-rays and CT scans show reticulations and opacities in the lung bases that can progress superiorly over time. Asbestosis can lead to pulmonary fibrosis and later development of pleuropulmonary malignancies.

1. ASBESTOSIS
Dr.I.Gurubharath MD PhD Dr.Pooja MD

2. ASBESTOSIS
• Chronic progressive diffuse interstitial pulmonary
fibrosis due to inhalation of asbestos fibers
• 20-30years after start of exposure
• Frequency: in 49–52% of industrial asbestos exposure
• Related to length and Intensity of exposure

3. Diagnostic criteria:
1. Reliable history of exposure
2. Appropriate time interval between exposure &
detection
3. Radiographic opacities classified as ILO s,t,u
4. Restrictive pattern of lung impairment
5. Diffusing capacity below normal range
6. Bilateral crackles at posterior lung bases NOT cleared
by cough

4. • Dyspnea
• Restrictive pulmonary function tests: progressive reduction
of vital capacity & diffusing capacity
• Location: lower posterior bases > apices Site
• Most severe in subpleural zones (asbestos fibers
concentrate beneath visceral pleura)

5. Chest Xray:
• Small irregular linear opacities progressing from fine to
coarse reticulations:
• Confined to lung bases, progressing superiorly
• Septal lines (fibrous thickening around secondary
lobules)
• Honeycombing (uncommon)
• “Shaggy” (obscured) heart border ( parenchymal +
pleural changes)
• Ill-defined outline of diaphragm
• Rarely massive fibrosis, predominantly at lung bases
without migration toward hilum
(ddx from silicosis / cwp)
• Absence of hilar / mediastinal adenopathy

6. A: Chest radiograph shows irregular, geographic areas of calcification corresponding to pleura
plaques seen en face. An increase in reticular opacities is visible at the lung bases.
B: Lateral chest radiograph shows slight posterior displacement of the major fissures (white
arrow) resulting from fibrosis and volume loss in the posterior lung bases. An increase in
retirular opacities is visible posteriorly

7. HRCT:
• Thickened intralobular lines as initial finding
Multiple subpleural curvilinear branching lines
(“subpleural pulmonary arcades”)
Dot like reticulonodularities connected to the most
peripheral branch of pulmonary artery
site: most prominent posteriorly parallel to and within
1 cm of pleura
• Thickened interlobular septal lines

8. Reticulations , network of linear densities, usually
posteriorly at lung bases
Architectural distortion of lobule
• Parenchymal band formation linear < 5 cm long &
several mm wide opacity, often extending to pleura,
which may be thickened & retracted at site of contact
• Patchy areas of ground-glass attenuation
• Honeycombing ( multiple cystic spaces < 1 cm in
diameter with thickened walls)

9. HRCT features of early asbestosis include subpleural lines (arrowheads) and fine
reticulation (arrows).

10. C. CT in soft tissuewindow shows calcified pleural plaques and areas of pleural thickening
D. CT lung window shows fibrosis with honeycombing in the lung periphery

11. Complications:
Pulmonary fibrosis,
Pleuropulmonary malignancy (latency period of > 20
years)
Differential Diagnosis
Idiopathic pulmonary fibrosis (NO parietal pleural
thickening

12. ATELECTATIC ASBESTOS PSEUDOTUMOR
ROUND ATELECTASIS /“FOLDED LUNG” /Blesovsky syndrome
• Infolding of redundant pleura accompanied by segmental /
subsegmental atelectasis
• Most common of benign masses caused by asbestos exposure
• Location: posteromedial / posterolateral basal region of lower
lobes (most common); frequently bilateral - 2.5–8 cm focal
subpleural mass abutting a region of thickened pleura
• size & shape show little progression, occasionally ↓ in size

13. CT:
• Rounded / lentiform / wedge-shaped peripheral mass
• Pleural thickening ± calcification always present and
frequently greatest near mass
• “crow’s feet” linear bands radiating from mass into lung
parenchyma (54%)
• “vacuum cleaner” / “comet” sign , bronchovascular
markings emanating from nodular subpleural mass,
coursing toward ipsilateral hilum
• “Swiss cheese” air bronchogram (18%)
• partial interposition of lung between pleura + mass
• volume loss of affected lobe ± hyperlucency of adjacent
lung

14. A.Chest Xray PA view Shows Peripheral
Well definrd opacity
B.Contrast CT axial view a.Soft tissue
density in both lower lobes.lesions
adhere to the pleura forming acute
angles.

17. REFERENCES:
1. Webb WR, Higgins CB. Thoracic imaging: pulmonary and
cardiovascular radiology. Lippincott Williams & Wilkins;
2010.
2. Adam A, Dixon AK, Gillard JH, Schaefer-Prokop C,
Grainger RG, Allison DJ. Grainger & Allison's Diagnostic
Radiology E-Book. Elsevier Health Sciences; 2014 Jun 16.
3. Dahnert WF. Radiology review manual. Lippincott Williams
& Wilkins; 2017 Mar 9.
4. www.Radiopedia.org

18. THANK YOU