This week, the fair is in town. That’s right – the Coastal Carolina Fair is here! Honestly, I think the fair is better for people watching than anything else, as paying five dollars to lose a game which is impossible to win or eating fried butter sticks are not really for me. But I do love the rides! I have always loved roller coasters and rides with height or speed. Every time I go, I want to do the Gravitron. You know the ride – you stand up with your back against the wall, it spins very fast, and the floor drops out. Inevitably, someone will say it makes him or her sick or claustrophobic.
This week’s Ask Dr. Geier column reminds me of people’s fear of the Gravitron. For most people, an MRI is not a scary procedure, but some people are claustrophobic. As always, please refer to my disclaimer about discussing medical information via e-mail or online.
Gwen in South Carolina asks:
I have a question regarding MRI’s. I need to have one on my shoulder, but I am claustrophobic. Can I get an open MRI, or do I need to have a regular one?
This is an excellent question, and it is one that I’m not sure I can completely explain. I asked William F. Conway, MD, PhD and Thomas L. Pope, Jr., MD, Professors of Radiology at MUSC and musculoskeletal radiologists who work with MUSC Sports Medicine, to help me understand and explain the “open” versus “closed” MRI debate.
First of all, the terms “open” and “closed” MRIs refer to the size of the hole, or tube, in which the patient lies. The two main advantages of an open MRI compared to a close one are their ability to be used by very large patients and by patients who are claustrophobic. Unfortunately up to 10% of patients who undergo MRIs do get claustrophobic. “It’s always nice to have an open magnet alternative to closed magnets to avoid having to give a patient sedation, which is well known to have risks,” Dr. Pope points out.
The main question with open MRIs has always been the quality of the images and studies. I personally have always worried about ordering a study on an open magnet and finding out after it has been performed that the study is not a high quality one. Dr. Pope notes, “The newer open magnets out there have strength up to 0.7 Tesla, which produce very reasonable images.” Dr. Conway agrees and points out, “The protocols set up by the radiologists, including the specific sequences used, often matter much more than the signal strength of the magnet.”
Closed MRIs do have advantages. According to Dr. Pope, “Closed magnets have higher field strengths, which in theory can produce better images. Also, their data acquisition is faster, which can potentially lead to shorter procedure times for the patients.”
In summary, how do you know which type of MRI is best for you? If you’re not grossly overweight or claustrophobic, it still seems that a closed MRI study on a 1.5 or 3 Tesla magnet, especially if the musculoskeletal radiologists optimize the protocols, is a worthy option. For the larger or claustrophobic patients, though, current open MRIs done with appropriate protocols can be a reasonable alternative. If you’re not sure about the quality of the studies done where you are scheduled to have an MRI, call the facility. “Patients can always call the hospital or radiology facility and ask whether there is an open magnet and the strength of the magnet,” Conway emphasizes.