Reticular Patterns

Upper Lobe Reticular Pattern : C-A-S-S-E-T

• Cystic Fibrosis
• Ankylosing Spondylitis
• Sarcoid
• Silicosis
• Eosinophilic Granuloma
• Tuberculosis

Lower Lobe Reticular Pattern : B-A-D-L-A-S-S

• Bronchiectasis
• Asbestosis
• Drug Reactions
• Lymphangitic Metastasis
• Sarcoid
• Scleroderma / Collagen Vascular Disorders (Rheumatoid Arthritis)

Diffuse Fine Reticular Densities:

(From Chest Radiology: Plain film patterns and differential diagnoses by James C. Reed)

This pattern must be distinguished from the normal pattern of blood vessels. The best way to do this is to demonstrate the presence of Kerley B lines which represent thickening of the interlobular septa that extend to the pleural surface.

Acute Etiologies:

1. Pulmonary Edema:

Pulmonary interstitial edema is probably the most common cause of a diffuse, fine reticular pattern

A. Cardiogenic

B. Non-cardiogenic:

• Uremia
• Fluid Overload
• Severe hypoproteinemia: Cirrhosis and nephrosis

2. Infection:

• Viral pneumonia
• Mycoplasma pneumonia
• Pneumocystis pneumonia

Chronic Etiologies:

1. Chronic Pulmonary Edema:

• Mitral stenosis

2. Collagen Vascular Disease:

• Rheumatoid lung
• Systemic Sclerosis

3. Inhalational Lung Disease:

• Asbestosis
• Silicosis (More commonly has a combination of small nodules and fine reticulations)

4. Idiopathic Causes:

• Idiopathic pulmonary fibrosis
• Idiopathic pulmonary hemosiderosis
• Alveolar proteinosis
• Lymphangiomyomatosis

5. Granulomatous disease:

• Sarcoid (More commonly presents with small, nodular densities)

6. Lymphangetic metastases

7. Lymphatic Obstruction

• Mediastinal mass or adenopathy
• Lymphangiectasia