There are two major types of MRI scans, contrast and non-contrast. The primary difference is that for contrast MRIs, a dye (gadolinium-based) is given to the patient intravenously prior to the scan. Non-contrast MRI is great option for patients for whom dye is not recommended, pregnant women and kidney-compromised patients. Non-contrast also provides greater images of blood vessel activity, detecting aneurysms and blocked blood vessels. Your doctor will determine which is appropriate, depending on what diagnostic information he or she is trying to obtain. Most orthopaedic studies are done without contrast.
The use of a contrast agent may be ordered by a physician who wants a more-detailed look at a particular part of the body. The injectable dye can be admitted intravenously to highlight areas of inflammation or directly into a joint (arthrogram). Physicians have the ability to manipulate the images to achieve a better look at a particular area in which they have interest.
If there are tumors and other abnormalities in your body, they will absorb the contrast dye, and this area will glow on the MRI scan. Small tumors, which may not be visible on X-ray or CT Scan, may be detected by MRI. The contrast helps detect even the smallest tumors, and it can give your doctor more clarity regarding the location and size of a tumor and which organs or tissues are involved.
MRI contrast may have an effect on other conditions such as allergies, asthma, anemia, hypotension (low blood pressure), kidney disease, and sickle cell disease. There are some possible side-effects from using contrast, including:
- Shortness of breath
- Allergic reaction
- Blood clots
If you experience any abnormal symptoms, consult a medical professional or the emergency room, if necessary. All patients have the right to decide what medical testing and treatment they would like to receive. If you fear the injection or possible contrast side-effects, please discuss this with your physician or the MRI technician. They will be able to explain in greater detail why the contrast has been ordered for you. There are many conditions that do NOT require contrast for an MRI. Do not be afraid to ask your doctor to explain why he or she may order contrast for you.
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