Dr Mazen QusaibatyMD, DIS

Head Pulmonary and Internist Department Ibnalnafisse Hospital

Ministry of Syrian healthEmail:

Qusaibaty@gmail.com

1. Types of Atelectasis

2. Occupational lung disease

3. Comet tail sign

2

Topic Outline

1. Types of Atelectasis2. Occupational lung disease3. Comet tail sign

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Types of Atelectasis

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Definition of Atelectasis

• The loss of air in the alveoli• Alveoli devoid of air (not

replaced)

Muller, NL, Fraser, RS, Colman, NC, et al. Radiologic diagnosis of diseases of the chest. Saunders, Philadelphia, 2001.

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Types of Atelectasis

Obstructive

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Types of Atelectasis

Obstructive

No obstructive

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Obstructive Atelectasis

Atelectasis Right Upper Lobe

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Types of Atelectasis

Obstructive

No obstructive

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No obstructive

Relaxation

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Relaxation Atelectasis / Mechanical Atelectasis

Massive right pneumothorax

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No obstructive

Relaxation

Compressive

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Compressive Atelectasis

Chest wall masses

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Compressive Atelectasis

Chest wall masses

Pleural masses

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Compressive Atelectasis

Chest wall masses

Pleural masses

Loculated collections of pleural fluid

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Compressive Atelectasis

Chest wall masses

Pleural masses

Loculated collections of pleural fluid

Intraparenchymal masses

Lead to a diminution in lung volume below the usual resting volume

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Compressive Atelectasis

Posterior

Loculated

collections

of pleural fluid

Courtesy of Paul Stark, MD.

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Compressive Atelectasis

Posterior

Loculated

collections

of pleural fluid

Compressed

right lowe

r lobe

Courtesy of Paul Stark, MD.

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No obstructive

Relaxation

Compressive

Adhesive

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Qualitative or

quantitative

surfactant

abnormalities

Adhesive Atelectasis

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Qualitative or

quantitative

surfactant

abnormalities

Alveolar

collapse

Adhesive Atelectasis

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Qualitative

or quantitative surfactant

abnormaliti

es

Alveolar collaps

e

Reduce

the ventilation

-perfusion ratio

Adhesive Atelectasis

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Adhesive AtelectasisARDS is an example of diffuse

alveolar atelectasis

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No obstructiveRelaxation

Compressive

Adhesive

Replacement

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Replacement Atelectasis

• Occurs when the alveoli of an entire lobe are filled by tumor

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Replacement AtelectasisBronchioloalveolar Cell

Carcinoma

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No obstructive

Relaxation

Compressive

Adhesive

Replacement

Cicatrization

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Cicatrization Atelectasis

• Results from diminution of volume as a sequel of severe parenchymal scarring

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Granulomatous disease

TB Sarcoidosis

Necrotizing pneumonia Radiation

Cicatrization Atelectasis

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Cicatrization Atelectasis

Silicosis

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Cicatrization Atelectasis

Silicosis

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No obstructive

Relaxation

Compressive

Adhesive

Replacement

Cicatrization

Rounded

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Types of Atelectasis

Obstructive

No obstructive

Relaxation

Compressive

Adhesive

Replacement

Cicatrization

Rounded

Occupational lung disease

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Occupational lung disease

Inhalation or Ingestion

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Occupational lung disease

Inhalation or Ingestion

• Dust particles• Noxious chemicals

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• Pneumoconiosis• Chemical pneumonitis• Occupational infection• Hypersensitivity pneumonitis• Organic dust toxic syndrome

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PneumoconiosisSilicosis

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PneumoconiosisSilicosis

Asbestosis

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PneumoconiosisSilicosis

Asbestosis

Berylliosis

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PneumoconiosisSilicosis

Asbestosis

Berylliosis

Foreign body granulomatosisTalc

Cellulose and starch

Cotton-wool fibers

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Chemical pneumonitis

• The term chemical pneumonitis refers to the aspiration of substances that are toxic to the lower airways, independent of bacterial infection.

• Mendelson's syndrome.

Mendelson, CL. The aspiration of stomach contents into the lungs during obstetric anesthesia. Am J Obstet Gynecol 1946; 52:191.

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Occupational infection

• Viral and Bacterial infections at health workers

• Parasitic infections : Echinococcus disease

Comet tail sign

Comets

Comets are made up of ice and dust

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Comets

• The center of a comet is called a nucleus and is the only part that is solid.

• It is made from ice, rock and dust

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Comets

• Usually a comet has 2 tails, a white or yellow dust tail and a blue gas tail.

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Rounded Atelectasis

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Rounded Atelectasis

Historically called

folded lung syndrome

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Rounded Atelectasis

Historically called

folded lung syndrome

helical atelectasis

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Rounded Atelectasis

Historically called

folded lung syndrome

helical atelectasis

Blesovsky syndrome

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Rounded Atelectasis

Historically called

folded lung syndrome

helical atelectasis

Blesovsky syndrome

pleural pseudotumor

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Rounded Atelectasis

Historically called

folded lung syndrome

helical atelectasis

Blesovsky syndrome

pleural pseudotumor

Pleuroma

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Rounded Atelectasis

Usually located inPosterior and lower

zonesLingula

Right middle

lobe

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Rounded Atelectasis

• It presents as a subpleural mass

• Segmental or subsegmental atelectasis

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Rounded Atelectasis

Generally in association with pleural disease :

1. pleural plaque2. pleural

thickening 3. Or a currently

present or resolving pleural effusion.

Comet tail

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Staples CA. Computed tomography in the evaluation of benign asbestos-related disorders. Radiol Clin North Am 1992; 30:1191-1207 / Lynch DA, Gamsu G, Ray CS, Aberle DR. Asbestos-related focal lung masses: manifestations on conventional and high-resolution CT scans.Radiology 1988; 169:603-607.

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Comet tail

Bronchovascular bundles (Bronchi and

blood vessels)

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Comet tail

Bronchovascular bundles (Bronchi and

blood vessels) as they enter

the atelectatic

lung parenchyma

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Comet tail

Bronchovascular bundles (Bronchi and

blood vessels ) as they enter

the atelectatic

lung parenchyma that extend

from the lower border of the mass to the hilum

Rounded Atelectasis

• All rounded atelectasis is actually round.

60Lynch DA, Gamsu G, Ray CS, Aberle DR. Asbestos-related focal lung masses: manifestations on conventional and high-resolution CT scans.Radiology 1988; 169:603-607.

Rounded Atelectasis / Atypical features

Wedge-shapedLentiformOr (less often) irregular opacities or

attenuation

61Batra P, Brown K, Hayashi K, Mori M. Rounded atelectasis. J Thorac Imaging 1996; 11:187-197.

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Rounded Atelectasis

• Volume loss of the affected lobe is uniformly present

• Often with hyperlucency of the adjacent lung.• Serial examination usually shows a stable

appearance

Batra P, Brown K, Hayashi K, Mori M. Rounded atelectasis. J Thorac Imaging 1996; 11:187-197.

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Approximately 70 % of cases are associated with:

Previous Asbestos exposure

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Approximately 70 % of cases are associated with:

Previous Asbestos exposure

Pleural Tuberculosis

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Can

Persist for years

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Can

Persist for years

Clear spontaneously

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Can

Persist for years

Clear spontaneously

Grow rarely

Rounded atelectasis in the right lung

A nodular mass in the right mid-lung (long arrow).

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Rounded atelectasis in the right lung

A tail-like connection is seen between the mass and the hilum (short arrow).

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CT scan of rounded atelectasis in the right lower lobe

A subpleural mass in the right lower lobe with tentacle-like extensions towards the hilum (arrow)

Comet tail signBronchovascular bundles (Red arrows)

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What is your diagnosis ?

Klebsiella pneumonia74

• Sequential 2-mm, nonenhanced CT scans

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• Bronchovascular bundles (solid

arrow) appear to be pulled into the mass in a curvilinear fashion

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• Pleural thickening (arrowhead) is present

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• The major fissure (open arrow) is displaced posteriorly owing to the volume loss in the right lower lobe

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CT scans and autopsy findings in an 86-year-old man with silicosis (former metal ore miner).

Transverse CT scans obtained with 10-mm collimation.http://radiology.rsna.org/content/236/2/685/F8.expansion.html

80

CT scans and autopsy findings in an 86-year-old man with silicosis (former metal ore miner).

Lung window scan shows a rounded opacity in the right lower lobe. http://radiology.rsna.org/content/236/2/685/F8.expansion.html

81

CT scans and autopsy findings in an 86-year-old man with silicosis (former metal

ore miner).

Lung volume is reduced

http://radiology.rsna.org/content/236/2/685/F8.expansion.html

82

CT scans and autopsy findings in an 86-year-old man with silicosis (former metal

ore miner)

The major fissure is displaced (arrows)http://radiology.rsna.org/content/236/2/685/F8.expansion.html

Mediastinal window scan at the same level as in a shows a thickened band (arrow) that connects Progressive Massive Fibrosis (PMF) with the thickened pleura.

http://radiology.rsna.org/content/236/2/685/F9.expansion.html

There is a small amount of ipsilateral pleural effusion and multiple calcifications in the PMF

http://radiology.rsna.org/content/236/2/685/F9.expansion.html

Rounded Atelectasis / Silicosis

• Gross lung specimen from a coronal section shows diffuse pleural thickening in the right lung base and invagination (arrow) into the mass

http://radiology.rsna.org/content/236/2/685/F10.expansion.html

Elastic-Goldner stain, original size / Silicosis

• Silicotic nodules forming the mass (Blue color)

• Interstitial fibrosis and atelectasis (Black color)

• Thickened pleura (arrows) (Blue color)

http://radiology.rsna.org/content/236/2/685/F11.expansion.html

A 50-year-old man with asbestos exposure from working in a brake lining production plant

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Asbestosis

• Chest radiograph shows:• Diffuse thickening of

the left pleura• Curvilinear band

opacities in the left lower lung zone

88http://radiographics.rsna.org/content/21/6/1371/F16.expansion.html

High-resolution CT scan (mediastinal windowing) /Asbestosis

• pleural plaques on the right side (small white arrows)

89http://radiographics.rsna.org/content/21/6/1371/F17.expansion.html

High-resolution CT scan (mediastinal windowing) /Asbestosis

• Rounded atelectas on the left side  (large white arrow)

90http://radiographics.rsna.org/content/21/6/1371/F17.expansion.html

High-resolution CT scan (mediastinal windowing) /Asbestosis

• Diffuse pleural thickening (black

arrows) on the left side.

91http://radiographics.rsna.org/content/21/6/1371/F17.expansion.html

High-resolution CT scan (mediastinal windowing) /Asbestosis

• Pleural plaques along the diaphragmatic contour (black arrows)

92http://radiographics.rsna.org/content/21/6/1371/F18.expansion.html

High-resolution CT scan (mediastinal windowing) /Asbestosis

• An irregular attenuation pattern, which is typical in rounded atelectasis (white

arrows).

http://radiographics.rsna.org/content/21/6/1371/F18.expansion.html

High-resolution CT scan (lung windowing) obtained at the level of the liver dome /Asbestosis

• A visceral pleural plaque in the right major fissure (arrow)

http://radiographics.rsna.org/content/21/6/1371/F19.expansion.html

High-resolution CT scan (lung windowing) obtained at the level of the liver dome /Asbestosis

• Curvilinear bands of hyperattenuation in the posterior subpleural area

http://radiographics.rsna.org/content/21/6/1371/F19.expansion.html

High-resolution CT scan (lung windowing) obtained at the level of the liver dome /Asbestosis

• Rounded atelectasis + posterior displacement of the left major fissure.

http://radiographics.rsna.org/content/21/6/1371/F19.expansion.html

High-resolution CT scan (lung windowing) obtained at the level of the liver dome /Asbestosis

• The diagnosis of asbestosis was proved at open lung biopsy

http://radiographics.rsna.org/content/21/6/1371/F19.expansion.html