Radiology · Year 4 · from Radiology
Case 1: Lobar Pneumonia with Air Bronchograms
Patient Demographics
- Age: 67 years
- Sex: Male
Chief Complaint
Productive cough and fever for 4 days
Presenting Symptoms
The patient presents with a 4-day history of productive cough with rust-colored sputum, fever up to 39.4C, and progressive shortness of breath. He reports right-sided pleuritic chest pain that worsens with deep inspiration. He has a 40 pack-year smoking history and continues to smoke. He denies recent travel, sick contacts, or immunosuppression.
Physical Exam Findings
- Vital Signs: Temp 38.9C, BP 138/82 mmHg, HR 102 bpm, RR 24/min, SpO2 91% on room air
- General: Ill-appearing male in mild respiratory distress
- Pulmonary: Decreased breath sounds over right lower chest, dullness to percussion at right base, egophony and bronchial breath sounds over right lower lobe, increased tactile fremitus
- Cardiovascular: Tachycardic, regular rhythm, no murmurs
Imaging Findings and Interpretation
Chest Radiograph (PA and Lateral):
- Dense consolidation involving the right lower lobe
- Air bronchograms visible within the consolidation (air-filled bronchi surrounded by airless lung)
- Silhouette sign: Right hemidiaphragm is obscured (consistent with right lower lobe involvement)
- Right heart border remains visible (excludes middle lobe involvement)
- No pleural effusion visible
- No mediastinal widening
- Cardiothoracic ratio within normal limits
Radiographic Interpretation: The presence of lobar consolidation with air bronchograms in a febrile patient with productive cough is classic for bacterial pneumonia. The preservation of the bronchial tree (air bronchograms) indicates the airways are patent and the process is alveolar filling rather than atelectasis. The right heart border visibility with right hemidiaphragm obscuration confirms right lower lobe localization based on the silhouette sign.
Diagnosis
Community-acquired pneumonia, right lower lobe - likely Streptococcus pneumoniae given lobar distribution and clinical presentation
Management
- Hospitalization given hypoxemia and severity (CURB-65 score: 2)
- Supplemental oxygen to maintain SpO2 >92%
- Empiric antibiotics: Ceftriaxone 1g IV daily + Azithromycin 500mg IV daily
- Blood cultures and sputum culture obtained before antibiotics
- Urinary pneumococcal and legionella antigens
- Follow-up chest radiograph in 6-8 weeks to document resolution and exclude underlying malignancy given smoking history
Radiological Image
Image Description: Chest radiograph demonstrating right lower lobe consolidation with visible air bronchograms, indicating alveolar filling while bronchi remain patent. The right hemidiaphragm is obscured (silhouette sign), confirming lower lobe involvement.
Source: Wikimedia Commons - "Chest X-ray in influenza and Haemophilus influenzae, with areas of consolidation" URL: https://commons.wikimedia.org/wiki/File:Chest_X-ray_in_influenza_and_H_influenzae.jpg License: Creative Commons Attribution 2.0 Generic