MRI Scans Using Contrast Dyes
Before an MRI scan is conducted, the doctor sometimes injects the patient with a special kind of dye, called contrast. This dye is mostly made of a chemical substance called gadolinium, which consists of complex molecules held together in a strong chemical bond. The contrast dye is injected intravenously before the MRI scan is begun and is eliminated from the body via kidneys. In most of the cases, a contrast dye is not needed. The use of contrast mostly depends on a number of different conditions. For example, if the doctor has noted certain things about the diseases which can only be sought with a contrast MRI, only then it will be employed.
A contrast dye is sometimes used to give more clear and accurate images of the body. It is also used to improve the quality of the scans and makes it easier to see the tissues that are hard to detect. The most common reasons to use these contrast dyes include a history of tumors, cancer, surgery, search for infection or inflammation, and assessment of blood vessels.
Although there are a number of advantages of using MRI with contrasts, however, there are some side effects as well. These side effects can be divided into various types that are described below:
The common side effects of using contrast dyes are those which are very normal in nature. Hence, they do not require any special treatment. These side effects may include, nausea, low blood pressure, mild headache, minor skin rash, and pain or burning at the injection site. According to a study published by the Mayo Clinic, it was reported that out of 450,000 patients who participated in the study, only 0.04% reported side effects after administration of the contrast dye for MRI scan. The most common side effect reported was nausea and rashes at the injection site. The study also reported that only 19 patients out of 450,000 experienced severe side effects and one person died due to contrast dye for MRI scan.
Allergic reactions due to contrast dyes are not very common. According to a study published in the American Journal of Roentgenology in 2008, out of the 78,353 patients who participated in the study, only 54 of them experienced acute allergic reactions. The most common allergic reactions are swelling of the face, rashes, itchy eyes, sweating, and shortness of breath. Usually, the reactions are mild and can often be controlled with medication. However, if they are left untreated they can become serious and even life-threatening.
This is one of the most serious kinds of side effects reported. As the dye exits the body via kidneys, it becomes difficult for the patient with renal failure, to make this process quicker. Thus, the dye remains in the body for a longer period of time and causes nephrogenic systemic fibrosis. The symptoms include muscle tightening, joint pain, yellow spots on the eye, and sometimes internal organ dysfunction. All in all, how minor it may be, it is advised to consult your doctor as soon as you see any symptoms of allergic reactions after a contrast MRI scan.