HRCT of Common Lung Diseases. W. Richard Webb MD

HRCT of Common Lung Diseases W. Richard Webb MD

Common Lung Diseases: HRCT Infections (pneumonia, airways disease) Sarcoidosis Hypersensitivity pneumonitis UIP and idiopathic pulmonary fibrosis (IPF) Nonspecific interstitial pneumonia (NSIP) Organizing pneumonia (OP or BOOP)

Sarcoidosis microscopic noncaseating granulomas in clusters 60-70% have characteristic plain film findings 10% have normal chest radiographs HRCT abnormal in most with normal radiographs

Sarcoidosis: HRCT findings small nodules, usually well-defined are typical patchy distribution upper lobe predominance in most the nodules show a perilymphatic distribution typical lymph node enlargement or calcification in some patients is suggestive, but is not necessary for diagnosis

Sarcoidosis: Nodules perilymphatic nodules predominate in relation to the peripheral pleural surfaces and fissures, and the peribronchovascular interstitium interlobular septal nodules are less frequent and less numerous centrilobular nodules can be seen involving the centrilobular peribronchovascular interstitium in rare patients, the nodules appear random in distribution

Sarcoidosis Subpleural and peribronchovascular nodules

. Perilymphatic nodules in sarcoidosis: peribronchovascular and subpleural

. Sarcoidosis: interlobular septal nodules

. Sarcoidosis with interlobular septal nodules

. interlobular septal nodules with atypical basal distribution

. Centrilobular (peribronchovascular) nodules

. Sarcoidosis: centrilobular opacities mimicking tree-in-bud

Sarcoidosis: centrilobular nodules

. Sarcoidosis: nodules with a random distribution

Sarcoidosis: additional findings large nodules or masses - 15-25%» often upper lobe, parahilar (peribronchovascular)» air bronchograms (i.e. consolidation)» confluence of granulomas» satellite nodules ( galaxy sign )» alveolar sarcoid ground-glass opacity» confluence of small granulomas

Sarcoidosis: subpleural and peribronchovascular nodules confluent nodules: masses with satellites.

Sarcoidosis: subpleural and peribronchovascular nodules confluent nodules: masses with satellites the galaxy sign.

. confluent nodules: masses with satellites

. Sarcoidosis: confluent nodules with air bronchograms

Sarcoidosis: confluent nodules with air bronchograms

. Sarcoidosis: clustered small nodules with satellites and ground-glass opacity

. Sarcoidosis: nodules and ground-glass opacity

. Sarcoidosis: ground-glass opacity

Sarcoidosis: airway abnormalities obstruction of large airways endobronchial granulomas small airway obstruction with mosaic perfusion and/or air trapping on expiratory scans

Sarcoid: airway abnormalities

45 year old with dyspnea. bronch: sarcoidosis

. 1 year later

Sarcoidosis: nodules and air trapping dynamic expiration.

. Sarcoidosis: subpleural and peribronchovascular nodules

Sarcoidosis: air trapping dynamic expiration inspiration.

Sarcoidosis: air trapping dynamic expiration.

Sarcoidosis: late or fibrotic nodules decrease (but often remain visible) distortion of fissures, reticulation interlobular septal thickening peribronchovascular fibrosis, usually upper lobe conglomerate masses of fibrous tissue traction bronchiectasis subpleural honeycombing in a few percent emphysema and cysts

. Sarcoidosis: early fibrosis with reticulation and distortion of fissures

. Sarcoidosis: fibrosis with reticulation and septal thickening

. Sarcoidosis: conglomerate fibrosis, traction bronchiectasis, posterior displacement of the hila

. Sarcoidosis: fibrosis with traction bronchiectasis

. Sarcoidosis: peribronchovascular fibrosis with traction bronchiectasis, mild honeycombing

. Sarcoidosis: traction bronchiectasis and cysts

. Sarcoidosis: fibrosis with cysts

. Sarcoidosis: traction bronchiectasis, cysts, emphysema, aspergilloma

. Sarcoidosis: traction bronchiectasis and honeycombing

Hypersensitivity Pneumonitis

Hypersensitivity Pneumonitis (HP) common caused by inhalation of organic antigens responsible antigen identified in only 50% acute, subacute, and chronic stages repeated exposures produce fever, chills, dry cough, dyspnea progressive symptoms over months or years

Hypersensitivity Pneumonitis: subacute stage ongoing exposure progressive symptoms over weeks to months ill-defined peribronchiolar granulomas alveolitis and interstitial infiltration cellular bronchiolitis

Hypersensitivity Pneumonitis: subacute stage ill-defined centrilobular nodules (50-60%), usually of ground-glass opacity (granulomas) patchy ground-glass opacity (75-90%) (alveolitis) patchy mosaic perfusion; air trapping on expiratory scans (bronchiolitis) diffuse or predominant in mid lung zones; entire cross section of lung involved; no subpleural predominance a few lung cysts in a few patients

. Subacute hypersensitivity pneumonitis

Subacute HP: patchy GGO

Hypersensitivity pneumonitis post-treatment ground-glass opacity.

ground-glass opacity + mosaic perfusion ground-glass opacity = interstitial infiltration mosaic perfusion = bronchiolitis. Headcheese sign

Headcheese sign. Hypersensitivity pneumonitis

Hypersensitivity Pneumonitis Headcheese sign lobular (geographic) ground-glass opacity and mosaic perfusion (air trapping) indicative of mixed infiltrative disease and bronchiolitis

. mosaic perfusion

. expiration

66 year old bird fancier with progressive dyspnea. Hypersensitivity pneumonitis

dynamic expiration. Hypersensitivity pneumonitis

Subacute HP: air trapping

. Biopsy proven HP

. expiratory scan

Hypersensitivity pneumonitis expiration air-trapping with lung cyst.

HRCT Diagnosis: Chronic HP, IPF, NSIP chronic HP: lobular areas of low attenuation, centrilobular ground-glass opacity nodules, absence of lower lobe predominance IPF: basal predominance of honeycombing, absence of subpleural sparing and nodules NSIP: subpleural sparing, absence of honeycombing and lobular low attenuation confident diagnosis in 53%; correct in 94% Silva et al. Radiology 2008; 246:288

48 year old man with dyspnea

Hot tub lung

Hot tub lung Immunocompetent subjects symptoms within hours of hot tub use dyspnea, cough, hypoxemia, fever nonnecrotizing granulomas, often bronchiolocentric MAC (mycobactium avium) found on culture, less often on biopsy, and in the hot tube likely a hypersensitivity reaction resolution without antibiotic treatment

Hypersensitivity Pneumonitis: chronic stage long term or repeated exposure irregular fibrosis: coarse scars, septal thickening, traction bronchiectasis, honeycombing in some patchy, lacks a subpleural distribution in most diffuse or predominantly involving mid lung zones upper lobe involvement (atypical for IPF) superimposed findings of subacute disease in some: ground-glass opacity or nodules headcheese sign with findings of fibrosis

Hypersensitivity Pneumonitis: progression. 6 month follow-up

. Chronic HP

. chronic HP: reticulation and traction bronchiectasis

. chronic hypersensitivity pneumonitis

subacute HP: ground-glass opacity chronic HP: reticulation and traction bronchiectasis.

HRCT of Common Lung Diseases W. Richard Webb