Radiology/Heat sensation during MRI-scan
Recently I had to undergo a cervical MRI-scan. Immediately after the machine was started, I began to feel an intense heat in the examined area. It felt like my neck was being microwaved. I had to stop the examination. I had several MRI scans before without any trouble. It seems to be a rare complication, but according to some studies I have read it does happen sometimes. My radiologist suggested avoiding 3T-machines and opting for the less powerful 1.5T ones. Have you got any explanation for this heat sensation or an idea how I can avoid it in future? Due to my medical condition I should have the scan soon, but I am a bit hesitant after this experience. During the exam I neither had any metal nor any other objects with me that could have interfered with the MRI. Is it possible for an MRI-scanner to malfunction and, for example, use too much energy?
Thanks for your help,
I agree with your radiologists's recommendation that you avoid 3T scanners. Images from a 1.5T scanner are perfectly acceptable and considered the industry standard. Because a 3T magnet is twice as strong as a 1.5T, I can imagine that heating side-effects might be greater in the 3T. I have no first-hand experience on a 3T magnet, though.
During an MRI, you are exposed to radio-frequency (RF) radiation. The RF energy causes increased oscillation of molecules and generation of heat. So, it is expected that your body temperature will increase slightly during an MRI. But it should not be unbearable.
I found an excellent technical article about how MRI technology works and affects biological tissue, which may answer some of your questions: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2705217/
To avoid overheating during an MRI in the future, I recommend you always use a 1.5T scanner. An accurate weight is required to calibrate the appropriate amount of energy to use on each patient. You could become overheated if the weight entered is greater than your actual weight. I weigh every patient before they enter my scanner room. Not everyone does this, so be sure you know exactly how much you weigh at your MRI appointment.
Be sure your clothing has NO METALLIC components. I just read about some patients being burned during an MRI because they were wearing clothing made from material containing metallic thread. During their MRI, the metallic threads became heated and burned the patient's skin.
So, wear cotton or nylon with no zippers, etc. I have scrubs for my patients to change into. Those are perfect attire for MRIs.
Don't hesitate to have another MRI when necessary. Be sure an tell your MRI tech about the troubles you've had previously. That way, (s)he'll be extra-careful to make sure things go well for you next time.
Hope this helps,