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Imaging Saves Lives

Have you ever had an X-Ray, CT, MRI, an ultrasound, or a mammogram? 

Then a radiologist was involved with the outcome of your exam. Whether interpreting your study behind-the-scenes or in-person consult, their involvement set your life on a new course. Sharing your experience can inspire and help others in their health journey, because knowing you’re not alone may make all the difference.

About Your Exam

X-Ray (Radiography)

X-rays were discovered in 1895, and within a very few years the use of x-rays to provide simple images of the lungs and the bones had spread around the world. X-rays were originally used to develop images on film, much like a photograph. Increasingly in developed countries film is being replaced by detector plates that transmit a digitized image to a computer screen. This form of technology is now known as either computed radiography (CR) or digital radiography (DR). Fluoroscopy uses pulses of low-dose x-rays to provide images in real time that can be used to guide diagnostic and therapeutic procedures such as angiography (detailed x-rays of the blood vessels), biopsies, and the placement of drainage tubes or stents.

Computed Tomography (CT Scan)

A CT scanner consists of an x-ray tube and x-ray detectors mounted on opposite sides of a circular gantry that are linked to a very powerful computer. The x-ray tube emits radiation while the patient passes through the hole in the centre of the gantry. The X-ray detectors on the other side of the patient’s body relay detailed information about the body part that has been scanned to the computer. The computer uses this information to construct multiple cross sectional images or “slices” of the body. There has been continual development in CT technology in the years since its invention in 1971, and state-of-the-art scanners can now generate very detailed images of the body in multiple planes. CT scanners can detect many abnormalities that “plain” x-rays cannot, although usually with a higher x-ray dose.

Magnetic Resonance Imaging (MRI Scan)

Magnetic resonance imaging uses a combination of an extremely powerful magnet, radio waves and powerful computers to generate cross sectional images of the body. No X-rays are involved. The powerful magnetic field can however interfere with the function of certain devices such as pacemakers and implanted stimulators or pumps, making MRI generally unsafe for patients with these devices. Patients with certain types of older aneurysm clips used to treat brain aneurysms also cannot undergo MRI for safety reasons.

The MRI gantry fits more tightly around the patient than a CT scanner, and some patients with claustrophobia may have difficulty having an MRI. Claustrophobic patients should request a prescription for an oral sedative from their doctor before the MRI examination.

MRI is often the procedure of choice to evaluate certain diseases involving the soft tissues. MRI examinations are generally more expensive than CT however, and require more time to perform (30 to 60 minutes or even longer). As MRI does not use x-rays, there is no concern about radiation dose.


Ultrasound uses high frequency sound waves that are directed into the body using a transducer. The sound waves are reflected back toward the transducer by tissues, and a computer uses the information in the reflected waves to generate an image. The study is generally performed by a highly trained technologist called an ultrasonographer. Because it does not use x-radiation, it is very useful if medical imaging is required during pregnancy. It can be used to provide images of the soft tissues and blood vessels, and also to guide intervention such as biopsies and drainages. It cannot provide images through air or bone however, and therefore cannot be used to image the lungs and cannot see through air-filled bowel loops.


Mammography is the process of using low-dose X-rays to examine the human breast. The goal of mammography is the early detection of breast cancer, typically through detection of characteristic masses, architectural distortion and/or microcalcifications. Mammography reduces mortality from breast cancer. No other imaging technique has been shown to reduce the death rate, but breast self-examination (BSE) and physician examination are considered part of regular breast care.

Mammography does not find all cancers. This is partly due to dense tissues obscuring the cancer and the fact that the appearance of cancer on mammograms may overlap with the appearance of normal tissues.

Mammography also finds many abnormalities that are not cancer. Women may be understandably distressed to be called back for a diagnostic mammogram. Most of these recalls will not be cancer, but radiologists would rather be “safe-than sorry,” so try not to worry if you’re called back for extra pictures. Some women even need a needle biopsy to determine whether cancer is present, or not. These are done usually with either ultrasound or mammogram guidance. Local anaesthetic (freezing) is given first. It stings about the same, or less, than the sting when blood is taken from the arm. Once the freezing is in, only dull pressure is felt. So a needle biopsy is only slightly “more glamorous” than a blood test!

A mammogram is a quick and easy X-ray of the breast done in complete privacy by a specially trained female technologist.

Who interprets the results and how do I get them?

A radiologist, a physician specifically trained to supervise and interpret radiology examinations, will analyze the images and send a signed report to your primary care or referring physician, who will discuss the results with you. You will also be notified of the results by the mammography facility.


Imaging of the breast improves a physician’s ability to detect small tumors. When cancers are small, the woman has more treatment options and a cure is more likely.


Five percent to 10 percent of screening mammograms require more testing such as additional mammograms or ultrasound, etc. Most of these tests turn out to be not cancer. If there is an abnormal finding, a follow-up or biopsy may be recommended.

The risk of the radiation from a mammogram actually causing a breast cancer is negligible. The doses used are very small. It’s estimated that out of a million mammograms performed, that theoretically, one cancer might be caused. The data from the BC Screening Mammography Program show that women who have mammograms have over 40% fewer deaths from breast cancer than women who do not have mammograms, so even if there’s a theoretical risk of one cancer being caused (per million mammograms), the risk of dying from it is less. In other words, the benefit far outweighs the potential risk.

Mammograms are the most important tool doctors have, not only to screen for breast cancer, but also to diagnose, evaluate, and follow people who’ve had breast cancer. They are safe and reasonably accurate, and have been in use for over 50 years.


What is a radiologist?

A radiologist is a physician who has at least 13 years of post secondary training.  These doctors have trained for at least four years in the speciality of diagnostic radiology after obtaining his or her MD. The training includes the modalities of  radiography (“plain” X-ray images), ultrasound, CT and MRI. Some radiologists may also obtain training in Nuclear medicine. Many radiologists perform an additional one-to-two years of sub-specialty training in a particular area of the body or a particular imaging modality.

Radiologists receive training in radiation physics and in techniques to minimize radiation dose during diagnostic and therapeutic studies.

Radiologists study the normal anatomy of the body as it is demonstrated by the various imaging modalities; they also learn the changes from normal anatomy that are produced by disease processes throughout the body. As such, the radiologist is aware of the strengths and limitations of each imaging modality, and is ideally qualified to recommend the most appropriate imaging modality for a particular health problem.

What is interventional radiology?

Interventional radiology uses imaging techniques to guide a number of therapeutic procedures that are performed by radiologists. These procedures are generally minimally invasive, meaning that they require only very small skin incisions, and produce minimal damage to normal tissue. Many of these procedures use blood vessels to gain access to certain tissues, and in fact many blood vessel problems can be treated by catheters that are introduced into the arteries or veins. Balloons and stents can be used to open blood vessels that have become narrow or blocked. Various devices can be introduced into blood vessels to intentionally block vessels to control bleeding or tumour growth. Some brain aneurysms can be treated by introducing coils through the arteries to fill the aneurysm; some aneurysms or tears of the aorta can be repaired with stents introduced through the arteries.

I am breast feeding and have received an injection of dye as a part of my CT scan or MRI scan. Should I be concerned about breastfeeding my baby?

Until a few years ago it was routinely recommended that mothers not breast feed their babies for 24 hours if they had received an injection of iodine dye for a CT scan, or an injection of gadolinium for an MRI scan. It has recently been determined however that the amount of these substances that is excreted into breast milk is extremely small. Furthermore, the proportion of the substances that is absorbed by the baby from breast milk is also extremely small and poses no risk or discomfort to the baby. It is now recommended that mothers continue to breast feed their babies as usual following these procedures.

Is there a safe level of radiation exposure for a patient during pregnancy?

In general, if medical imaging is required during pregnancy, radiologists will seek to use other imaging modalities such as ultrasound and MRI that do not use X-rays in order to protect the baby. If after careful consideration it is determined that a procedure using X-rays will provide important information that is not provided by other imaging modalities, then this procedure will be recommended in the best interest of the mother and the baby. Precautions will be taken to minimize the radiation dose in these circumstances.

How does diagnostic radiology aid diagnosis and treatment of diseases?

Radiology helps the diagnosis and treatment of diseases by providing us with images of what were looking inside of our bodies. It allows us to do this without having to cut into the body, which is a huge advantage that wasn’t available three generations ago.

What conditions or diseases can diagnostic radiology help diagnose?

Some of the conditions that radiology can help diagnose include infections or cancers as well as congenital abnormalities and inflammatory diseases.

What are some different types of diagnostic radiology?

Some of the various aspects of diagnostic radiology include plain x-rays, which many patients are familiar with from broken bones when they have to go to the emergency room and have an x-ray of their ankle or of their hand. There are other forms of radiology imaging including CT scans, MRI scans, ultrasound and mammography.

Medical Imaging Directories

These links are provided for reference and convenience and should not be considered a comprehensive list.

Health Authority and Community Imaging Clinics

The HealthLink BC Find Services webpage provides listings for health services provided by the provincial government, provincial health authorities, and publicly-funded community imaging clinics. You may either type in an agency/program name, or choose a suggested service as you type (x-ray, ultrasound, CT, MRI). Enter your location/postal code then click the button.

Independent Clinics

The Find Private Clinics website offers a directory of private clinics (user-pay) in Canada which you can filter by province and medical specialty.

Accredited Diagnostic Imaging Facilities in BC – Public and Private

The Diagnostic Accreditation Program is a branch of the College of Physicians & Surgeons of British Columbia that establishes, evaluates and monitors performance standards in diagnostic health care, and administers accreditation programs that include diagnostic imaging in both public and private diagnostic irrespective of their funding source. All facilities undergo a comprehensive assessment according to their scope of service prior to being awarded accreditation.


The content of our website is for informational purposes only. It is intended for residents of Canada only. It is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on our website. The British Columbia Radiological Society (BCRS), their subsidiaries, affiliates, or other contributors to this website cannot be held responsible, whether directly or indirectly, for any harm, injury, damage, loss or inconvenience which might arise from the use of this website or from your reliance on any information provided on this website.

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