What is an MRI Scan?

MRI scans are imaging investigations that GPs refer to help diagnose certain medical conditions and problems. During the procedure, patients are required to lie on a table that runs through a tunnel. Whilst in the MRI machine, strong magnets are used to take detailed images inside the body. Unlike other scans, MRI scans are non-invasive as they do not emit any radiation. However, there are some risks that should be discussed with your GP.

What is an MRI scan used for?

GPs and medical professionals will refer patients for MRI scans to thoroughly assess the area of interest. It can almost be used to examine any part of the body. However, for some situations, an MRI alone may not be enough to determine what is occurring. Depending on your current issue, your doctor may request an MRI to help diagnose, monitor and decide on the next appropriate step for your care. Common areas that MRIs may be used to investigate include:

Internal organs (e.g. liver, prostate, etc.)
Blood vessels and heart
Brain and spinal cord
Bones (e.g. spine, pelvis, etc.)
Joints (e.g. knee, hip, etc.)
Soft tissue (e.g. ligament, tendon, breasts etc.)

What does an MRI show?

An MRI uses the body’s magnetic properties to recreate a 2D or 3D view(s) inside the region of interest. Medical professionals will often refer for MRI scans because they provide highly detailed images. It will show typical structures, such as muscles, ligaments and organs but also identifies any abnormalities. Examples of conditions or abnormalities that MRIs can help pick up includes [3]:

Injuries or conditions to the joints (e.g. cartilage damage, ligament sprains, etc.)
Spinal abnormalities (e.g. nerve-related problems, trauma, etc.)
Soft tissue conditions (e.g. tumours, infections, etc.)
Damage to the internal organs
Brain conditions (e.g. epilepsy, tumours, swelling, etc.)
Abnormalities of the heart and blood vessels (E.g. heart disease, blockages, etc.) [4]

MRI Scan Risks and Precautions

While MRI scans emit no radiation, they also come with some risks and precautions. One common problem is that patients may need to remain still for the duration of the investigation. The confined areas in the MRI machine can pose a problem for claustrophobic individuals. Options such as sedatives or music can help make this process more tolerable [1]. Additional considerations, include [3]:

The need to fast in some circumstances. You will be notified beforehand if there are any requirements.
Removing unnecessary objects that may interfere with the procedure, including watches, credit cards, mobile phones, jewellery, etc.
Any implanted objects that may disrupt the MRI machine (e.g. pacemakers, dental implants, electrical devices, infusion pumps, orthopedic prostheses, etc.). Inform your GP or referring healthcare professional beforehand if you possess any of these devices.
Aggravating previous symptoms of hearing loss.
Any potential allergies to the contrast dye that needs to be injected before the MRI scan. Pregnancy. While typically safe, please inform your GP about whether you could be or are pregnant.

Alternative Imaging Techniques

Other imaging investigations that can also be performed include:

Plain X-ray
CT Scans
Ultrasounds

Compared to these diagnostic tests, MRIs emit no radiation and provide highly detailed scans. However, results taken from MRI scans often take longer than these other imaging techniques. As a result, MRI may not be appropriate in situations where timing is essential (i.e., emergencies).

CT Scan vs MRI

One of the most common comparisons to CT scans is MRIs. Differences between these two imaging investigations have been summarised in the table below [3][5].

CT Scans	MRIs
Results can be obtained within 24 hours.	Results may require 1-2 weeks to be processed.
During the procedure, a small dose of ionising radiation may be emitted.	No radiation is emitted during this procedure. Strong magnets are used instead.
Procedures are generally quick and take within 10-20 minutes.	MRIs are usually slower and may take over 90 minutes.
Provides detailed images of all structures, including bone, soft tissue and blood vessels.	MRIs provide even a greater deal than CT scans, particularly of the internal organs (e.g. brain, heart, etc.)

MRI Scans - Frequently Asked Questions (FAQ)

What does an MRI stand for?

MRI stands for Magnetic Resonance Imaging. This is just one of the imaging techniques that your GP may opt to use to investigate for certain conditions.

What does an MRI stand for?

MRI stands for Magnetic Resonance Imaging. This is just one of the imaging techniques that your GP may opt to use to investigate specific conditions.

How does an MRI work?

Unlike other imaging techniques, such as x-rays and CT scans, MRI machines use magnets instead of radiation. You will be required to lie flat inside the large magnetic machine as a radiographer operates the scan [2]. Once the scan is complete, a medical specialist called a radiologist would interpret what is seen on the scan. MRI machines utilise the body’s significant water and fat reserves to create detailed 2D and 3D images of the investigated area [3]. Both fat and water contain hydrogen molecules (also known as protons), allowing the body to have some naturally occurring magnetic properties. During the procedure, the magnets inside the machine can alter the movements of these protons. Energy detected from these movements are collected by sensors in the MRI machines, which turns this information into pictures of the area. Commonly, diseases and conditions in the body will contain more water which can be picked up by these scans [3].

How Long Does an MRI Take?

The duration of an MRI will depend on what the GP has ordered and the assessed area. As a result, the MRI can take between 10 minutes to over an hour to complete [1]. There may be additional time required when accounting for set-up and preparation.

How much does an MRI cost?

According to the Australian Diagnostic Imaging Association (ADIA), the average upfront cost per MRI service is $526 [6]. Prices may vary depending on the area of interest and your circumstances. Medicare arrangements can be provided so that some of the costs may be covered, which will require you to pay a gap instead. Your GP may be able to assist with some of these arrangements.

What is an MRI Scan? An Essential Patient Guide

What is an MRI Scan?

What is an MRI scan used for?

What does an MRI show?

MRI Scan Risks and Precautions

Alternative Imaging Techniques

CT Scan vs MRI

MRI Scans - Frequently Asked Questions (FAQ)

What does an MRI stand for?

What does an MRI stand for?

How does an MRI work?

How Long Does an MRI Take?

How much does an MRI cost?

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