Fell over recently and broke a bone? Got a niggling pain in one of your joints? Have a sports-related injury that just won’t go away?
When you visit your doctor for a diagnosis, they may recommend you undergo one of several scans. Dr Leon Foo, orthopaedic surgeon at Mount Elizabeth Hospital, shares some common tests used to detect bone and joint problems.
What is it? An x-ray uses electromagnetic waves of energy, which pass straight through your body, to take an image of your bones and organs. Because each area of your body absorbs energy differently, your bones will appear white on an x-ray, while soft tissues exhibit shades of grey. Don’t panic if your lungs look black—that’s because they contain air!
What does it scan for? X-rays have a multitude of uses. If you’ve injured yourself and your doctor suspects a broken (fractured) bone, you’ll probably need an x-ray to confirm this and determine the extent of damage.
Your doctor may also suggest an x-ray if they suspect:
- Arthritis (inflamed joints)
- Bone cancer or infection
Who is it for? Anyone can have an x-ray. If you’re experiencing pain in one of your bones or joints, or you’ve injured yourself, your doctor may recommend you have one.
Fortunately, x-rays are standard procedures that carry minimal risks. While they do use ionising radiation, the level of exposure is considered safe for most adults. The only exception is if you are pregnant, as the radiation could harm your baby. Speak to your doctor if you’re expecting a child and they will be able to recommend an alternative procedure.
What can you expect during the procedure? A special imaging plate will take pictures of your body. You will be helped into the right position, which might be sitting, standing or lying down. If the position involves moving an injured bone or joint, you may feel some discomfort during the test. If you’re worried about this, your doctor will be able to prescribe you pain medication in advance.
You’ll need to stay still during the x-ray procedure to ensure your doctor gets the clearest images possible. Thankfully, taking x-rays are generally very quick and the image is often taken within a split second.
Any special preparations required? No—just remember to take off your jewellery and any metal objects as these can block x-rays from passing through your body and obscure the image!
Computed tomography (CT) scan
What is it? A CT scan uses a combination of x-ray machines and advanced computers to create a 3D image of your body. They provide far more detailed images than a plain x-ray, displaying solid organs, soft tissues and any abnormal growths as well as your bones.
What does it scan for? You may need a CT scan if your doctor wants to examine your bones in more detail. Conditions that affect the spine, such as scoliosis (curved spine) or vertebral fractures, may require a CT scan so that your doctor can see the affected area in its entirety. Your doctor may also recommend a CT scan to detect non-cancerous growths (like cysts) or cancerous tumours, or to measure the density of your bone (to determine the severity of osteoporosis).
Who is it for? A CT scan can be used on almost any part of the body, from the head and shoulders to the knees and legs, to diagnose bone disorders, bone fractures or bone cancer. As it’s a minimally invasive procedure, there are few risks aside from some ionising radiation exposure.
What can you expect during the procedure? You’ll need to lie down to have your CT scan. You’ll then be transported into the scanner, which will rotate around you and take hundreds of pictures, for a few minutes.
Depending on which area of the body is being tested, your doctor may need to use a special ‘highlighter’ dye called contrast to help your internal organs, tissues and blood vessels show up more clearly in the final images. You can often drink a harmless liquid containing this. Alternatively, your doctor may sometimes inject it into your arm or insert it via a rectal enema.
Any special preparations required? If your procedure requires contrast, you may need to avoid eating for up to 6 hours prior to the procedure. Otherwise, the CT scan isn’t so very different from having an x-ray (above) – it just takes a little longer!
Magnetic resonance imaging (MRI) scan
What is it? A MRI scan is a non-invasive procedure that combines a large magnet, a computer and magnetic waves to take images of your bones and organs. MRI scans are different from CT scans in that they take much longer, but the advantage is their images have more radiological detail and, most importantly, they do not expose you to ionising radiation.
What does it scan for? Your doctor can use a MRI scan to check your bones, joints, cartilage, muscles and tendons. So if you’re experiencing unexplained pain in any of these areas in your body, your doctor may recommend you have a MRI to pinpoint the cause.
MRI scans can also be used to diagnose:
- Inflammatory diseases like arthritis
- Abnormalities that may have been present from birth
- Infections such as osteomyelitis (bone infection)
- Bone marrow disease
- Degeneration of the spinal cord (usually age-related)
Who is it for? Because MRI scans don’t use ionising radiation, they are generally considered safe for most people, including pregnant women past the first trimester, as well as young children. However, the scans do use magnets, so patients with a pacemaker or any metal implants (depending on the make and model of their device) may not be able to undergo the procedure.
If you’re claustrophobic, speak to your doctor about taking some anti-anxiety medication beforehand. For severely claustrophobic patients, there is also the option of monitored sedation by an anaesthetist during the scan.
What can you expect during the procedure? You’ve probably seen MRI machines on TV or in the movies—some people think they look scary, but there’s really no need to panic. Just lie down on the scanner bed, which will transport you into the machine itself, and stay very, very still so that the machine can take clear pictures of you. Your MRI technician will be able to communicate with you via an intercom system, so you can let them know if you’re feeling uncomfortable or you want the scan to stop.
MRI scans can last anywhere from 20 minutes to up to 2 hours, depending on the number of regions to be scanned.
Any special preparations required? Just like a CT scan, you won’t have to do much preparation before a MRI. You will however need to remove any jewellery or metal objects—especially important because the machine uses a magnet. Your doctor may also have to administer the contrast dye in the same way as for a CT scan.
Not sure if you need one of the scans listed above? Make an appointment with a doctor to learn more about your health condition.