Upper Lung Zones

Lower Lung Fields

Central
Perihilar

Peripheral
Subpleural Sparing

Small Airway Disease

• Asbestosis
• Bronchiolitis
  • Sarcoidosis
• Bronchiolitis Obliterans
• Constrictive Bronchiolitis aka Obliterative Bronchiolitis 
• Follicular Bronchiolitis (external lymphoid tissue)
• Hypersensitivity Pneumonitis (HP) Introduction
  • Fibrotic Hypersensitivity Pneumonitis (HP)
• Mucus Plugging
• Obliterative Bronchiolitis aka Constrictive Bronchiolitis
• Respiratory Bronchiolitis ILD Introduction

Diseases Affecting Both Small Airways and Alveoli

Check Point Inhibitor Pneumonitis
Cryptogenic Organizing Pneumonia
Acute Eosinophilic Pneumonia
Hypersensitivity Pneumonitis
Immunotherapy Related  Pneumonitis

Associated Findings

• Consolidations Associated with Blood Vessels