Principle

How it is done

• X-rays are high energy radiation waves that can penetrate body parts to produce an image.
• Patient is positioned so that the body part to be evaluated is between the x-ray source and a device (cassette) that records the image.
• The patient must remain still (for a couple seconds) when the x-ray is taken.
• Most plain x-ray examinations consist of at least two views of a body part at right angles to one another (i.e. PA and lateral CXR).

Example Indications

• Chest x-ray
• Most commonly used imaging procedure
• Practically done in most hospitalized patients
• For evaluation of pulmonary or cardiac symptoms
• Abdomen
• Acute pain
• Bones and Joints
• Injuries
• Pain

Limitation

• Significant pathology can be missed
• Radiation exposure

Useful for

• It can be diagnostic with no additional imaging required.
• It serves as preliminary image to plan for more specific imaging studies like CT or MRI.
• Required for interpretation of other imaging procedures like V/Q lung scan.

Cost: $

Densities

Air: Dark

Liquid density: White

Fat: Gray

Bone: Dense white

Metal: Extremely dense white