There is a nodular interstitial pattern in the diffuse/lower lung distribution on CXR.

1. If this were an acute presentation this could be...
2. If this were a chronic presentation this could be...

Acute: Atypical infection such as miliary TB or disseminated fungal infection, viral.

Chronic: Mets.

There is a nodular interstitial pattern in the upper lung distribution on CXR.

1. If this were an acute presentation this could be...
2. If this were a chronic presentation this could be...

Subacute:

• Hypersensitivity pneumonitis
• Bronchiolitis, viral

Chronic:

• Sarcoid (reticular, nodes)
• Silicosis / CWP (calcified)
• Eosinophilic granuloma (cysts)

There is a reticular pattern in the lungs with low volumes on CXR.

Differential is:

Fibrosis of which there are many causes:

Upper lobes:

• sarcoid
• chronic hypersensitivity
• ankylosing spondylitis

Lower lobes:

• UIP, NSIP
• chronic aspiration

There is a reticular pattern with normal to increased lung volumes on CXR.

If this is an acute presentation, this could be:

Otherwise, this could be:

Acute:

• edema/infection

Others:

• emphysema
• cystic lung disease such as PCP
• bronchiectasis, cystic fibrosis

• UPPER: ankylosing spondylitis
• LOWER: asbestosis, RA, scleroderma

There is a CXR with the primary abnormality being prominently thickened septal lines.

If the symptoms were acute, this could be:

If chronic, this could be:

Acute:

• edema
• atypical infection

Chronic:

• lymphangitic Ca
• amyloid
• Kaposi's sarcoma

The primary findings on CXR are multiple cystic changes or lucencies in the UPPER lungs.

If there are acute symptoms, this could be:

If chronic, the differential includes:

Acute:

• PCP (upper)
• necrotizing pneumonia

Chronic:

• honeycombing (sarcoid, chronic EAA)
• bronchiectasis (CF)
• eosinophilic granuloma
• emphysema

• LAM - diffuse

The primary findings on CXR are multiple cystic changes or lucencies in the LOWER lungs.

If there are acute symptoms, this could be:

If chronic, the differential includes:

Acute:

• necrotizing pneumonia

Chronic:

• honeycombing (UIP)
• bronchiectasis (aspiration)
• alpha-1 antitrypsin emphysema

• LAM - diffuse

The CXR shows diffuse septal lines and nodules. There is a very limited differential.

If symptoms are acute, this is probably:

If chronic, then this is probably:

Acute: atypical infection

Chronic: lymphangitic carcinoma

*Depending on the look, you might add sarcoid.

Fibrosis

• Idiopathic (UIP, NSIP)
• Asbestos
• Collagen vasc dz
• Chronic hypersensitivity pneumonitis
• Drugs (amio/bleo)

Sarcoidosis

Lymphangitic carcinomatosis (nodules)

Pulmonary edema

Sarcoidosis

Infection (miliary TB w/ nodules)

HRCT: I see multiple air cysts in the lung.

If there are "central dots" these are likely due to:

If there are "peripheral dots" these are due to:

Some other cystic lung disease include:

Central dot = centrilobular emphysema

Peripheral dot = EG

Other:

LAM, Sjogren syndrome

PCP

Honeycombing

HRCT: The main pattern is honeycombing in the lungs.

My differential is (same as irregular lines):

Fibrosis

• Idiopathic (UIP, NSIP)
• Asbestos
• Collagen vasc dz
• Chronic hypersensitivity pneumonitis
• Drugs (amio/bleo)

Sarcoidosis

HRCT: The primary pattern is ground-glass centrilobular nodules throughout the lungs.

I'd be thinking of:

• Extrinsic allergic alveolitis
• Bronchiolitis
• - respiratory
• - infectious or viral
• Bronchioloalveolar cell CA

HRCT: There are diffuse solid nodules. The distribution is along the fissures bronchovascular bundles, interlobular septae, pleural and subpleural.

Diagnosis?

The differential for perilymphatic nodules is:

Sarcoidosis

Silicosis, CWP

Could also be lymphangitic carcinomatosis if there is septal thickening.

HRCT: There are diffuse solid nodules. They spare the pleural surfaces. Could there also be associated "tree-in-bud"? Perhaps.

My differential includes:

• Infection, such as bacterial, TB and MAI
• Bronchiolitis
• Hypersensitivity pneumonitis (ground glass)
• Aspiration
• Pulmonary LCH/EG

HRCT: There are diffuse solid nodules. Appears to be a random diffuse distribution, including the pleural surfaces.

My differential is:

Disseminated infection such as miliary TB, histo, or other fungal dz

Metastatic disease

HRCT: I see randomly distributed cysts and nodules of varying sizes.

What could look like this?

HRCT: I see ground-glass opacity and thickened interlobular septal lines, also known as _______.

The differential for this is:

"crazy-paving"

• alveolar proteinosis
• bronchioloalveolar carcinoma
• lipoid pneumonia
• drug toxicity (most common)

HRCT: I see patchy ground-glass opacities throughout the lungs.

Differential would be:

• Pulmonary edema
• Alveolar hemorrhage
• Drug toxicity
• Extrinsic allergic alveolitis
• Pneumocystis pneumonia
• Alveolar proteinosis
• Interstitial pneumonia

HRCT: Not only do I see ground glass opacities, but the vessels appear larger within the ground glass opacities, a pattern also known as ____________.

What images would I ask for next?

What is my differential?

"mosaic perfusion"

Expiratory CT.

+air trapping: obliterative bronchiolitis

no air trapping: vascular, usually chronic PE

There's a consolidation on HRCT showing a consolidation with a central sparing (reverse CT halo sign).

This is specific for ________

organizing pneumonia

also, Wegener's granulomatosis

Organizing pneumonia

*idiopathic

*non-specific reaction

*drug reaction

*post-infection

*collagen vascular dz

Sarcoidosis

Eosinophilic pneumonia

Neoplasm

*BAL
*Lymphoma