Imaging modalities, why and when? (X-Ray, US, CT and MRI)
With many different modalities for imaging it is hard to know which is the correct method and when is it needed? Here is some brief information which can equip you with knowledge when a scan is needed and the positives and negatives of each modality.
X-Rays: They are a form of radiation, and when passing through your body, bone and other dense objects block the radiation and look white on the film of the x-ray. The less dense tissues are hard to see and appear grey.
Pro’s: cheap (usually bulk billed); readily available, minimally invasive and high specificity for bone
Con’s: small amount of ionising radiation, doesn’t show adequately much soft tissue information
Used for assessing: bone degeneration, fractures, dislocations, tumours, infections
Ultrasound: Sends out high frequency sound waves and records the reflected sound or echoes to create and image.
Pro’s: cheap (can be bulk billed by referral from GP), no radiation
Con’s: doesn’t display bone well, requires skilled operator for clear image
Used for assessing: soft tissue injuries (tendons), abdominal and pelvic organs, vascular systems, pregnancy, guided injections
CT: It’s a more powerful and sophisticated x-ray that takes a 360-degree image of the spine, vertebrae and internal organs. It generates high-quality, detailed images of the body.
Pro’s: readily available, relatively cheap (some can be bulk billed by GP), detailed image which displayed bone and soft tissue properties
Con’s: ionising radiation, claustrophobia
Used for assessing: musculoskeletal disorders, trauma, appendicitis, cancer, heart disease, infection disease etc.
MRI: Magnetic resonance imaging and combines a strong magnet with radio waves to display a detailed image of the body.
Pro’s: no radiation, high quality imaging
Con’s: expensive (only some bulk billed by GP), not readily available, claustrophobia
Used for assessing: joint and bone problems, soft tissue injuries, nerve and disc issues, assessing treatment progress, brain abnormalities etc.
Imaging can be necessary to exclude some diagnoses, identify a correct diagnosis and monitor progression through injury. Sometimes imaging won’t change the course of treatment or rehab and can also be unnecessary due to expense or radiation exposure. Speak to your Osteopath or GP as to whether or not imaging would be the correct option for you.