Chest Radiology Guide for Residents

Aug 16, 2024

Introduction to Chest Radiology for First-Year Residents

This guide is intended for first-year Radiology residents starting their chest radiology rotation. We'll focus on understanding lines, stripes, and key structures on a chest X-ray, using a normal chest X-ray and CT as references.

Key Structures on a Chest X-Ray

1. Trachea

  • Location: A midline structure, slightly deviated to the right due to the left-sided aortic arch.
  • Corina: The point where the trachea ends, forming a triangular shape.

2. Paratracheal Stripes

  • Right Paratracheal Stripe: Bordered by the superior vena cava (SVC).
  • Left Paratracheal Stripe: Bordered by the left subclavian artery.
  • Visibility: Lucent, but can become denser due to lymph node enlargement.

3. Aortic Structures

  • Aortic Arch: Causes slight deviation of the trachea.
  • Descending Aorta: Should appear straight in young patients; obscuration may indicate a left lower lobe pathology.

4. Aortopulmonary (AP) Window

  • Normal: Concave due to fat.
  • Abnormal: Convexity or bulging can indicate enlarged lymph nodes.

5. Left-Sided Cardiac Structures

  • Pulmonary Artery: Forms the inferior border of the AP window.
  • Left Atrial Appendage & Left Ventricle: Form part of the mediastinal border on the left.

6. Right-Sided Cardiac Structures

  • Right Atrium
  • SVC: Forms the upper border; important for central line placement.

7. Azygoesophageal Line

  • Location: Interface between the azygos vein and esophagus with the adjacent lung.

Additional Structures

8. Hila

  • Evaluation: Should be similar in size and density.
  • Abnormalities: Differences can indicate pulmonary hypertension or enlarged lymph nodes.

9. Lungs

  • Assessment: Compare density, size, and check for abnormalities.

10. Pleura

  • Common Issues: Pleural effusion (fluid collection) and pneumothorax (air in pleural space).

11. Bones and Soft Tissues

  • Bones: Check for fractures, especially in trauma.
  • Soft Tissues & Abdomen: Look for free air, indicating possible perforation.

Important Radiographic Signs

Lateral Radiograph

  • Clear Spaces: Retro-sternal, retro-tracheal, and retro-cardiac.
  • Spine Sign: Used to detect lower lobe abnormalities; should become more lucent as you move inferiorly.

Hilar Structures

  • Left Upper Lobe Bronchus: Important landmark.
  • Pulmonary Arteries: Located around hilar structures.

Donut Sign

  • Indicates lymph node enlargement when opacity encircles the hilum on lateral view.

Resources

  • Recommended Textbook: Felson's Principles of Chest Radiology, 4th Edition, for comprehensive learning.

This guide is a basic introduction, and further reading and practice, as suggested in the mentioned textbook, will help deepen understanding.