Diffuse Alveolar Disease

Radiological Signs:

• Butterfly distribution / Medullary distribution

• Lobar or segmental distribution

• Air bronchogram

• Alveologram

• Patchy, confluent shadows

• Soft fluffy edges

• Acinar nodules

• Rapid changes

• No significant loss of lung volume

• Ground glass appearance on HRCT

Useful Clinical Classification:

• Acute

• Chronic

Acute Diffuse Alveolar Disease:

• Water

  • Pulmonary edema - Cardiogenic

  • Neurogenic pulmonary edema

• Blood

  • SLE

  • Goodpasture's syndrome

  • Idiopathic pulmonary hemosiderosis

  • Wegener's granulomatosis

• Inflammatory

  • Cytomegalovirus pneumonia

  • Pneumocystis carinii pneumonia

  • Influenza

  • Chicken pox pneumonia

  • Fat embolism

  • Amniotic fluid embolism

  • Adult respiratory distress syndrome

    • CT

Chronic Alveolar Disease:

• Alveolar proteinosis

• Alveolar cell carcinoma

• Mineral oil pneumonia

• Alveolar form of sarcoidosis

• Alveolar form of lymphoma

• Alveolar form of tuberculosis

• Alveolar metastases from cancer of the pancreas

• Desquamative interstitial pneumonia

General:

• Cannot tell whether there is co-existent interstitial disease.

• Alveolar and interstitial pattern can be evident in different portions of lung and is of diagnostic significance.

• Evolution of changes in x-ray helpful in the diagnosis.

• None of the x-ray findings are specific.

• History and the clinical setting under which the problem is encountered is of great help in diagnosis.

• Presence of co-existing findings helpful,  e.g., lympadenopathy, etc.

• Options for a diagnostic procedure is based on the working diagnosis:  Sputum evaluation, HRCT, bronchoalveolar lavage, brushing, TBB, open lung biopsy, VAT lung biopsy,  CBC, ID workup, auto-immune workup, Cardiac workup

• Distribution

  • Cortical

    • Eosinophilic pneumonia

    • BOOP

  • Lower lobes / Mineral oil aspiration