Basic X-ray

1. Basic Principles

Bones
- Appear gray-white.
- Heavily mineralized areas visible.
- Growth plates visible in children.
Air
- Appears black to dark gray.
- Normal in airways & lungs, GI tract.
- Air-fluid lines may be visualized.
Fluid
- Appears gray.

2. Chest X-rays (CXR) / Radiographs

Views
- PA (posterior-anterior): preferred; scapula do not obstruct lung fields.
- AP (anterior-posterior): heart may appear larger.

Qualities to Assess
- Rotation/Angle: twisted body or poor camera angle can distort heart size.
- Inspiration:
  - Diaphragms should be at 9th rib on full inspiration.
  - Normal curve expected.
  - Flat diaphragms & expansion beyond 9th rib → air-trapping (asthma, COPD).
- Exposure: must be adequate for clear structures.
Baseline Structures
- Trachea, carina, right & left mainstem bronchi.
- Lung fields, hilum, diaphragm.
- Cardiac silhouette, pulmonary arteries, aortic knob.
Systematic Approach
- Follow a step-by-step method to interpret CXR findings.

3. Common Clinical Findings on X-rays

Tracheal Intubation
- Placement visible on radiograph.
Right Mainstem Intubation
- May cause atelectasis.
Pneumothorax
- No lung markings.
- Mediastinal shift with tracheal deviation.
- Depressed left hemidiaphragm.
- Treatment: chest tube insertion (note number of holes in tube).

ARDS (Acute Respiratory Distress Syndrome)
- “Ground glass” effect.
- Multifocal bilateral airspace opacities.
- Perihilar & lower zone distribution.

4. Gastrointestinal & Abdominal X-ray Findings

Nasogastric (NG) Tube
- Tip should be below diaphragm.
- Tip remains left of spine.

Nasoduodenal Tube
- Crosses from left to right side of spine.
- Advances toward jejunum.

Small Bowel Obstruction
- “Stacked coin” appearance.
- Air-fluid levels visible on erect film.