X-Rays & Medical Imaging

Radiography is the most frequently used imaging method for visualizing the inside of the body. Images are produced when x-rays pass through a part of the body and internal structures (such as your bones and organs) block different amounts of radiation to create an image.

Computed Tomography (CT) uses special x-ray techniques to produce multiple images (slices) of the body. We produce the slices by rotating an x-ray tube around your body. Slices are usually taken approximately 1.25 - 5 mm apart and are used to create 2-D images of soft tissues (e.g., fat, muscles and nerves) and other structures not captured in conventional x-rays. 3-D images can be produced in some cases, depending on the equipment and computer software available. CT scans are particularly useful in the diagnosis of trauma, musculoskeletal disorders, cardiovascular disease, infectious diseases and cancer.

Learn more about CT scans.

Fluoroscopy is the use of x-rays to create movies as well as still images. These procedures and imaging use x-rays and contrast dyes to examine and treat a number of conditions.

• Fluoroscopic imaging is used to asses body function, such as swallowing. Fluoroscopic interventions include angiography and interventional radiology. Angiography is a diagnostic procedure used to examine the blood vessels for blockages and other conditions by observing the flow of blood in the veins and arteries.
• Interventional Radiology is a method of treatment where a radiologist, a specially trained physician, inserts small tubes, wires and other instruments into different vessels of your body (e.g., blood vessels and organs) guided by the images supplied in the x-rays. We often use interventional radiology as an alternative to higher-risk surgical procedures to enhance your quality of life.

Learn more about fluoroscopic imaging and interventional radiology.

A mammogram is an x-ray image of the breast, which can detect subtle differences in tissue density. These are specialized radiography units.

We use mammograms to detect abnormalities in the breast tissue, and to screen for and diagnose breast cancer. The breast is flattened or compressed to prevent movement, decrease the amount of radiation required, and produce the best image possible. Some of our sites perform both screening and diagnostic mammograms, while other sites only perform diagnostic mammograms. 
 
Learn more about mammograms.

We use bone density tests to measure the mineral density of bones. The test is done using special x-rays (called dual energy x-ray absorptiometry or DEXA) to measure the amounts of calcium and other minerals.
 
Learn more about bone density tests.

Magnetic resonance imaging (MRI) uses magnets, radio waves and a computer to produce detailed images of the body. MRI can detect tiny changes of structure in the body, particularly in the soft tissue, spinal cord and brain, abdomen and joints. We commonly use MRI for

• Sports-related injuries of the soft tissue and joints
• Diagnosing heart conditions
• Examining the chest and abdomen
• Examining the brain and spinal cord

Learn more about MRIs.

Ultrasound (also called sonography) uses high-frequency sound waves to produce images of the body. We move a transducer over the part of the body being imaged, which sends and receives sound waves that are then interpreted to produce an image on a computer screen. The interpretation of the sound waves is based on the length of time for the echo to bounce back and the character of the sound (i.e., whether it is a solid, water or gas).

Learn more about ultrasounds.

An echocardiogram (ECHO) uses sound waves (ultrasound) to create a picture or image of your heart. The recorded waves show the shape, texture and movement of your heart valves, as well as the size of your heart chambers and how well they are working.
  
Purpose of the test:

• Check your heart function after a heart attack
• Check the valves in your heart
• Detect heart tumours
• Detect any fluid leakage into the sac surrounding your heart
• Check the size, shape and motion of the various parts of your heart

Learn more about echocardiograms.

A transesophageal echocardiogram or TEE is a special type of heart ultrasound procedure when there are questions about your heart that cannot be answered by a routine heart ultrasound. This will provide clearer images of the heart structures without interference from the chest wall, ribs or lungs.

Your health is important to us and x-rays are only taken if needed. There is a small risk with any medical drug, test, or therapy. X-rays might very slightly increase cancer risk.

X-rays are used for mammograms, radiographs, and CT scans. When your doctor requests an exam that uses x-rays, it means that in their expert opinion the benefits gained from the imaging information outweighs any risk from the x-ray radiation.

There is very little risk from medical radiation. The main concern is the possibility of future cancer from the x-rays. The risk of cancer from an x-ray exam is a fraction of a per cent per exam, and might be zero. This risk is very small compared to the risk of naturally occurring cancer, which is between 14 per cent and 40 per cent. The dose you have received from past x-rays will not increase your chance of developing cancer from the current exam.

X-ray radiation dose is measured using millisieverts (mSv) just like temperature is measured using Celsius (°C).

Background radiation (the radiation in our environment) varies throughout our health region. Within the Interior Health region you get between 1.8 to 7.9 mSv per year depending on where you live.

Different exams require different amounts of radiation. More radiation is required to image thicker body parts. CT gives more detail and generally uses more radiation than x-ray exams.

As long as your exam is clinically appropriate, the health benefits of the x-ray diagnosis far outweigh the x-ray dose risks.

Nevertheless, we always try to reduce x-ray and CT doses through radiation safety and quality assurance initiatives.

In some cases there are alternatives to X-rays. Ultrasound (US) and Magnetic Resonance Imaging (MRI) do not use x-rays and do not increase cancer risk. However, US and MRI may not provide the diagnostic information needed. Doctors know the best exam to perform to maximize the health benefit to patients.

It is safe for children to have X-rays. The doctor who requests the x-ray determines if the health benefit of the exam outweighs any potential risks from radiation.

The amount of radiation used for children is lower than what is used for adult exams. Your doctors and Interior Health employees take extra precautions when performing x-rays on children.

It is safe for people who are pregnant to have X-rays. The requesting doctor, x-ray staff, and radiologists take great efforts to identify pregnant patients. In most cases, the health benefit of having the x-ray exam far outweighs the potential risk to the unborn child. Your doctors and Interior Health employees take extra precautions for both pregnant people and people of childbearing age. 

Be sure to notify your doctor or x-ray technologist if you are pregnant.
 

We have used patient shielding for x-ray exams for over 70 years. This practice is changing. Modern scientific studies show radiation risk from medical imaging is much lower than we thought. We now know that previous shielding practices are not necessary.

Learn more