MRI with Contrast: Everything You Need To Know

What is an MRI with contrast?

Magnetic resonance imaging (MRI) with contrast is a specialised diagnostic imaging tool that provides highly detailed images of the body’s internal structures by combining magnetic and radiowave imaging. 

Unlike X-rays or computed tomography (CT) scans, an MRI with contrast uses a contrast agent, typically gadolinium-based contrast agents (GBCAs), to enhance image quality. The contrast material is injected into your bloodstream and helps highlight specific areas, such as blood vessels, tumours, or inflamed  tissues, making abnormalities easier to detect.

How does it work?

Gadolinium dye interacts with the magnetic field created by the MRI machine. The gadolinium particles travel through your bloodstream, causing the targeted tissues to glow instead of appearing grey as they would during a normal MRI scan. This change enables your healthcare provider to gain a more comprehensive understanding of your body's processes.

GCBAs often come in several different types, based on:

1. Chemical composition

2. Magnetic properties

3. How they get dispersed through the body

4. How they are administered

5. Whether they are organ specific

Why do I need an MRI with contrast?

An MRI scan with contrast only occurs when your doctor orders and approves it. Not every MRI requires using a contrast agent. MRIs with and without contrast are both effective, and your doctor will determine which scan you need based on your present condition and based on your medical and health history. 

Some reasons your doctor may recommend an MRI with contrast include situations where they will need to:

• Detect tumours or assess their size and spread.

• Identify inflammation or infections.

• Evaluate blood flow and blood vessel abnormalities.

• Monitor conditions like multiple sclerosis or cancer progression.

While a contrast MRI provides the doctor with valuable information via the increased visibility, they usually will not order an MRI with contrast unless it is necessary. In most cases, medical conditions caused by work-related injuries, sports injuries, and back pain do not usually require MRI with contrast exams.

If you are worried about any of these conditions, don’t hesitate to request an appointment with Thomson Medical. Our specialist will help to answer any questions you have and provide you with tailored recommendations.

What are the different uses for an MRI with contrast?

MRI with contrast is used for various medical purposes, including:

Assessing multiple sclerosis

• Doctors often use contrast MRIs to track the progression of multiple sclerosis (MS). MRI scans have transformed how radiologists diagnose MS and are now the primary method doctors use to diagnose the condition.

• An MRI with contrast detects new lesions as they form, helping doctors learn how fast the condition is progressing. They also help the doctor evaluate the type of MS a patient has, which can be:

  • Primary progressive MS

  • Secondary progressive MS

  • Relapsing/remitting MS

Cancer diagnosis

• A contrast MRI makes parts of your soft tissue look more detailed. During the early development stages, tumours are harder to spot. Hence, a contrast MRI allows healthcare providers to better spot tumours as they start growing.

Image clarity

• The contrast MRI highlights specific parts of your soft tissue, helping the radiologist come up with a diagnosis of your condition due to the enhanced image quality.

• Standard MRI scans aren't able to identify moving fluids, such as blood in your arteries.  Your arteries and veins appear as “flow voids” without the dye and show up on your scan as plain black. Using the contrast dye, it helps make your bloodstream stand out and be detected in the scan images.

Other times your doctor may suggest getting a contrast MRI targeting specific organs to make a diagnosis based on your personal health conditions, such as:

• Brain:

  • Detect tumours

  • Diagnose and detect strokes

  • Diagnose multiple sclerosis

  • Diagnosing other infections

• Heart:

  • Evaluating blood flow

  • Monitor heart structure

  • Evaluate damage from heart disease

• Spine:

  • Identify spinal cord injuries

  • Detect herniated discs

  • Detect tumours

• Abdomen:

  • Diagnose liver disease, poor kidney function, or pancreatic abnormalities.

• Blood vessels:

  • Highlight blockages or aneurysms in arteries and veins.

What are the differences between an MRI with contrast and an MRI without contrast?

Both types are effective, but the choice depends on the level of detail required for diagnosis. Some differences include:

How do I prepare for an MRI with contrast?

Preparation steps include:

1. Arrive 15 to 30 minutes early for your appointment to fill out the necessary paperwork and allow time for the contrast injection process.

2. There is no need to fast if you receive GCBAs via injection or intravenous (IV) drip. However, if you are to be administered oral GCBAs, you may need to fast for at least 4 hours before the procedure.

3. Remove all metal objects (jewellery, watches, piercings) as they interfere with the magnetic field.

4. Wear loose, comfortable clothing, as you may need to change into a hospital gown for the procedure.

5. If you are claustrophobic, your doctor may administer a sedative before the scan.

Remember to inform the radiology staff beforehand if you:

1. Have allergies in case you may be allergic to gadolinium-based dyes

2. Have kidney problems such as severe kidney disease

3. Have metal implants or pacemakers

4. Are pregnant

These conditions may affect whether you can safely get a contrast MRI, so it is better to discuss with your doctor beforehand what is the best course of action based on your individual conditions.

What happens during the test?

1. You’ll lie on a motorised table that slides into the MRI scanner.

2. A sedative may be administered by a healthcare professional if necessary.

3. The MRI machine may produce loud noises during the scan, so you might receive a pair of noise-cancelling headphones.

4. Afterwards, the doctor will inject the gadolinium-based contrast dye into a vein in your arm. Some people may feel a cool sensation or metallic taste during this process.

5. During the procedure, it is common to feel a slight warmth in the scanned area. If you are unable to hold a position, are cramping, or suddenly feel uncomfortable with the warmth from the scan, let the technician know.

6. The scanner will take images before and after the contrast injection to compare results. Once the technician has completed the requested scans, the images will be reviewed to ensure that all are clear and correctly positioned. In some cases, a part of the scan may need to be repeated.

7. The entire procedure typically lasts 30–60 minutes.

What happens after the test, and how can I interpret the results?

Unless the procedure involved the use of sedatives, you can immediately resume your normal activities after the scan. If the procedure involved the use of a sedative, you will be taken to a recovery room and monitored until you can sit up steadily. 

Once you are able to stand, someone will need to drive you home. Ideally, that person will stay with you for 24 hours in the event of an unexpected side effect. You will also need to drink plenty of water to help flush out the contrast dye through your urine.

A radiologist will review and analyse your scan results before sharing them with the doctor who ordered the MRI. Your doctor will then review and discuss the findings with you during a follow-up appointment.

Are there any risks associated with getting an MRI with contrast?

In most cases, there will be no immediate or lasting effects from an MRI with contrast. However, while generally safe, there are some risks, such as:

• Mild allergic reactions (e.g., rash or itching) to the contrast dye

• Very small traces of gadolinium may remain in your body after the scan; however, no known harmful effects have been reported.

• Abnormal heartbeat

• Shortness of breath

• Severe pain, redness, swelling, or discharged at injection site

• For breastfeeding mothers, it is best to wait 24 to 48 hours before resuming breastfeeding

If you notice any unusual or severe symptoms, please contact your healthcare provider right away.

FAQ

What does an MRI with contrast test for?

It tests for tumours, inflammation, blood vessel issues, infections, and other abnormalities requiring detailed imaging.

Why would you order an MRI with contrast?

Doctors order MRI with contrast when precise images are needed to evaluate complex conditions like cancer progression or vascular abnormalities.

Can I drive myself after an MRI with contrast?

Yes, you can drive yourself home unless sedatives were used during the procedure.

Is an MRI better with or without contrast?

It depends on your condition; MRIs with contrast provide more detail but aren’t always necessary.

What are the disadvantages of MRI contrast?

Potential risks include mild allergic reactions and higher costs compared to non-contrast MRIs.

Is MRI with contrast more expensive?

Yes, it is generally more expensive due to the use of contrast dye and additional imaging steps.

How common is MRI with contrast?

It’s relatively common when detailed imaging is required but not routinely used unless specifically indicated by a doctor.

What are the advantages of getting an MRI with contrast?

A contrast MRI has many advantages, including:

1. Providing clearer and more detailed images.

2. Aiding in distinguishing normal tissues and abnormal tissues.

3. Reducing the need for additional scans by providing comprehensive results in one session.

4. Detecting small tumours or subtle abnormalities.

The information provided is intended for general guidance only and should not be considered medical advice. For personalised recommendations and tailored advice, please consult a specialist at Thomson Medical. Request an appointment with Thomson Medical today.