What are X-rays?

X-rays are a type of radiation known as electromagnetic waves and are used for diagnostic imaging purposes thanks to their ability to pass through human skin and tissue. This allows images to be captured which are used by physicians to diagnose and treat medical conditions.

X-rays are similar to visible light, but they are absorbed differently by different parts of the human body. The calcium in your bones absorbs the most amounts of X-rays, which is why they appear dense and white on an image. Fat and other types of soft tissue absorb lesser amounts of X-rays and appear grey in images. Air absorbs the least amount, which is why your lungs and other air-filled spaces appear black.

How is an X-ray taken?

To generate an image or a radiograph, the patient is positioned between an X-ray source and X-ray detector. The source is focused on the area being imaged and the machine is turned on. The X-rays travel through the patient’s body and is absorbed in different amounts by different tissues. The detector creates an image of absorbed X-rays which the doctor uses to determine the cause and treatment for the patient’s condition.

When are X-rays used?

X-rays are used to diagnose and treat various medical conditions, with the most common being to detect bone fractures. X-ray radiography is also used to detect tumours, infections, abnormal masses, foreign objects, dental problems, calcification etc. Other special diagnostic uses of X-Rays include:

Mammography: Imaging of the breasts to detect and diagnose cancer, tumours and other abnormal masses.

Fluoroscopy: A fluorescent screen is used to capture real-time X-ray images of diagnostic processes or movement inside the body.

Computed tomography (CT): X-rays are combined with computer processing to generate multiple cross-sectional images which can be combined to create 3-D images.

X-rays and other types of high-energy radiation are often used to treat tumours and cancers.