Why do I need a second MRI scan with contrast?

If your doctor has ordered a magnetic resonance imaging or MRI for you, it might be one with contrast. You may be wondering about the difference between an MRI without contrast and an MRI with contrast. Moreover, you may not know much about getting an MRI, what it does, what it's like to undergo one, and what it can show your doctor.

What Is an MRI?

MRI, also known as nuclear magnetic resonance imaging (NMRI) or magnetic resonance tomography (MRT), is a form of medical imaging. It's a method used by radiology to take pictures of the internal anatomy and physiological processes within the body. MRI machines have scanners that use radio waves, strong magnetic fields, and magnetic field gradients to produce images of the body's internal organs.

What Is an MRI With Contrast?

An MRI with contrast uses gadolinium-based contrast agents (GBCAs), a type of MRI dye, to deliver more explicit images, which helps your radiologist decipher your MRI results with greater clarity. During your MRI procedure, gadolinium-based dye is added, typically via intravenous injection. GBCA is a temporary dye that allows your technician to see your organs differently, changing how imaging modalities interact and view your body. After your MRI with contrast test is over, the contrast dye is absorbed into the body or excreted in the urine.

MRIs without contrast can also be helpful, but your doctor may opt for an MRI with contrast for highly detailed images. However, this depends on your health, the potential problem, and the body part(s) involved in the testing. An MRI with contrast is usually not required for sports injuries, injuries sustained at work, and back pain.

What an MRI with contrast can do is provide a better view of:

  • Tumors.
  • Blood vessels.
  • Inflammation.
  • The blood supply to specific organs.
  • Determining a cancer diagnosis.
  • Evaluating multiple sclerosis (MS).

Contrast MRIs Make Viewing More of the Internal Functions Possible

An MRI scan with contrast highlights particular areas of your soft tissue, which helps your radiologist and doctor make their diagnosis. In addition to helping your radiologist identify tumors or any other dramatic developments, it also allows a view of aspects within your body that aren't visible on an MRI without contrast.
For instance, a standard MRI can't capture moving fluids in the body, so it can't detect blood in your arteries. The contrast dye, in comparison, gives your radiologist and doctor a view of your bloodstream, as the dye causes it to stand out. Without the contrast, those areas of your veins and arteries will only show up on your scan as plain black, otherwise known as flow voids.

Further Advantages of MRIs with Contrast

When the radiologist administers contrast dye during your MRI, it usually means your doctor won't need to order any additional imaging scans due to the contrast MRI's ability to deliver detailed results the first time around. Measuring and evaluating tumors is far superior with a contrast MRI. Adding contrast enables the radiologist even to spot small tumors and provide the tumor's exact location. Interpreting the MRI with contrast is easier for the radiologist due to the enhanced image quality of the scans.

An MRI image consists of shades of gray that vary from white to black. In a standard MRI, hard bone and air don't show up on scans; they just appear as black areas, as they don't produce an MRI signal. When the radiologist injects the gadolinium dye, soft tissues, blood, spinal fluid, and bone marrow will appear from light to dark. Their appearance depends on the amount of fat and water in your tissues and the settings on the specific MRI machine.

On the completed scan, your doctor can then use these dark and light areas to compare normal and abnormal tissue. The targeted tissues will show up as glowing and bright white. This makes detection and evaluation straightforward for your radiologist and doctor. An MRI with contrast is also the best diagnostic tool for detecting and identifying tumors, determining whether they're benign or malignant, and the growth stage of the tumors. This is especially the case in taking images of tumors in major bodily organs such as your central nervous system or brain.

How Safe is the Contrast Medium, Gadolinium?

Gadolinium is the metal used in contrast MRIs due to how it travels through the body's magnetic fields. The FDA approved it in 1998, and it has been used worldwide on over 300 million patients. Today, 70% of all MRIs performed are with a gadolinium contrast solution, and adverse reactions have proved to be rare. The lifesaving potential of a contrast MRI far outweighs the risks of gadolinium.

Multiple Sclerosis

Contrast MRIs are very helpful in tracking how MS progresses in the body. MRIs with contrast have revolutionized how radiologists make an initial MS diagnosis. They're now considered the primary methodology for doctors diagnosing the condition. MRI with contrast is favored over other tests, as contrast MRIs show MS lesions with much greater clarity than all other methods of inquiry.

That's not to say that contrast MRIs are the only way MS can be diagnosed, as doctors can often see lesions fairly easily. However, the advantage of contrast MRIs is that they can detect the formation of new lesions, which helps doctors determine the progression of the disease, as well as how fast it's advancing. MRI with contrast also helps doctors diagnose what kind of MS a patient has, as there are multiple types of the disease, such as:

  • Primary progressive MS.
  • Secondary progressive MS.
  • Relapsing/remitting MS.

Cancer Diagnosis

MRI with contrast dye shows a more detailed view of your soft tissue when searching for possible tumors. From this view, it's easier to spot tumors as they grow. However, if you have a tumor just beginning its growth, it can be more difficult for the radiologist to spot, even with contrast. Still, it's a better choice than an MRI without contrast, as your radiologist has a better chance of catching tumors early, making treatment more successful.

To learn more about how to prepare for an MRI or what to expect during an MRI, visit Grapevine Imaging. We specialize in providing physicians with the best diagnostic care possible through imaging, including MRI with and without contrast.

MRI by Muffet is licensed with CC BY 2.0

2401 Ira E. Woods Ave, #600
Grapevine, TX 76051

(817) 488-9991