MRI With vs. Without Contrast: What's the Difference?
The main difference between an MRI with and without contrast is whether a contrast agent is injected into a vein during the scan. A non-contrast MRI makes detailed pictures without any injection. An MRI with contrast adds a gadolinium-based agent that can make certain tissues and problems easier to see. Your doctor chooses which one you need based on the question they want answered. Millenium MRI performs non-contrast MRI only, which covers many common joint, spine and brain exams.
This guide explains what contrast does, when doctors may order each type, how to prepare, and what to ask before your appointment.
Key takeaways
Both MRI with contrast and MRI without contrast can give useful, detailed images.
Contrast is given through an IV and can make some tissues, such as inflamed or abnormal areas, stand out.
Contrast does not automatically mean a "better" scan. Your doctor orders what fits the medical question.
Some exams are "with and without contrast," meaning pictures are taken before and after the injection.
Before your scan, tell the team about kidney problems, past contrast reactions, allergies, pregnancy and any implants.
What is the difference between MRI with and without contrast?
MRI uses a strong magnet and radio waves to make pictures of the inside of the body. It does not use X-rays.
Feature | MRI without contrast | MRI with contrast |
IV line | No | Yes |
What it shows | Anatomy and structure in detail | Structure plus how tissues take up the contrast |
Injection | None | Gadolinium-based contrast agent |
Typical use | Many joint, spine and brain questions | Some questions about tumors, infection, inflammation or blood vessels |
What a non-contrast MRI shows
A non-contrast MRI shows the size, shape and position of organs, bones, joints, nerves and soft tissue. Many MRI exams, including many for joint injuries and back pain, are done without contrast.
What contrast adds
Contrast agents, sometimes called "dye," change how certain tissues appear on the images. Areas with more blood flow or a leaky blood barrier, such as some tumors, infections or inflamed tissue, may "light up." This is called enhancement. Enhancement helps the radiologist describe a finding, but it does not make a diagnosis by itself.
What "with and without contrast" means
When an order says "with and without contrast," the technologist takes a set of pictures first, then gives the contrast through an IV, then takes more pictures. The radiologist compares the before and after images.
When might a doctor order contrast?
Your doctor decides based on your symptoms, history and what they need to see. In general, contrast may be considered to:
Look more closely at a mass or tumor
Check for infection or an abscess
Look at inflammation, such as in some brain or spinal cord conditions
Look at blood vessels
Check an area after surgery
Follow up on a finding from an earlier scan
Contrast is often not needed for many common questions, such as:
Many sports and joint injuries
Many cases of back or neck pain from disc problems
Some brain scans, depending on the concern
These are general examples, not rules. Two people with the same body part scanned may get different orders because their questions are different.
MRI vs. CT
Doctors sometimes choose between MRI and CT. MRI usually shows soft tissue in more detail, while CT is often faster and shows bone well. In an emergency, CT is often used first. CT uses X-rays, and its contrast agent is different from MRI contrast. Learn more in our guide to MRI vs. CT scans.
How to prepare for an MRI with or without contrast
Preparation depends on your exam. Always follow the instructions from your doctor and the imaging center. In general:
Ask your doctor whether your order is with contrast, without contrast, or both.
Complete the safety form and tell the team about any metal, implants or devices in your body.
Tell the team about kidney disease, past reactions to contrast, allergies, and if you are or might be pregnant.
Ask whether there are any food or drink instructions for your exam.
Keep taking your regular medicines unless your doctor tells you otherwise.
Millenium MRI does not perform contrast MRI. If your order includes contrast, ask your doctor where to schedule that exam. For a full walkthrough, see our complete guide to what to expect before, during and after your MRI.
Is MRI contrast safe?
Gadolinium-based contrast agents are widely used, and serious reactions are uncommon. Like any medicine, they can cause side effects in some people. Mild effects can include a cool feeling at the IV site, a headache or nausea. Allergic-type reactions can happen, which is why the team asks about past reactions.
People with serious kidney problems may need extra review before getting gadolinium. Your doctor and the imaging team will decide whether contrast is right for you. For more on staying safe, read the essential guide to MRI safety.
MRI machine safety
MRI does not use ionizing radiation. Its main safety concern is the strong magnet. Metal objects can be pulled toward the machine, and some implants and devices are not safe in the scanner or are safe only under specific conditions. That is why screening is so important. Bring your implant or device card if you have one, and let the care team decide.
What happens during the scan?
You lie on a padded table that slides into the scanner. The machine makes loud knocking and tapping sounds, so you will get earplugs or headphones. The technologist can see and hear you and will talk with you during the exam.
At centers that perform contrast MRI, a small IV is placed in your arm or hand, and the contrast is given partway through. Every exam at Millenium MRI is non-contrast, so there is no IV. Staying still helps keep the images sharp. Most patients at Millenium MRI are in and out in about 35 minutes, depending on the exam.
After the scan, a board-certified radiologist reads your images. Results usually go to your doctor within 24 hours.
Frequently asked questions
Which is better, MRI with or without contrast?
Neither is better in general. The right choice depends on what your doctor needs to see. Many scans give the needed answers without contrast.
How do I know if my MRI needs contrast?
Check your doctor's order or ask your doctor. The order will say "without contrast," "with contrast," or "with and without contrast."
Does an MRI with contrast take longer?
Often a little, because extra pictures are taken after the injection. The exact time depends on the exam.
Does Millenium MRI do MRI with contrast?
No. Millenium MRI performs non-contrast MRI only. If your doctor orders an MRI with contrast, ask your doctor where to schedule that exam.
Do I need a referral for an MRI at Millenium MRI?
Not if you pay cash. Self-pay patients do not need a referral. Insurance patients need a doctor's order.
Related reading
Schedule an MRI at Millenium MRI
Millenium MRI has centers in Ocala, Largo and Tamarac, Florida, and in Jonesboro, Marion, North Little Rock and Springdale, Arkansas. Self-pay MRI is $300 per scan in Florida and $500 per scan in Arkansas, with no referral needed. All of our exams are done without contrast. We are open Monday through Friday, 9am to 5pm.
This article is for general information and is not medical advice. Talk with your doctor about your specific situation.
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