Magnetic Resonance Imaging came about during the 1970s, providing a much clearer and more accurate picture of the internal environment of a living human body. Basically, an extremely strong magnetic field is used to interact with the nuclear magnetization of atoms in the body, providing RF fields with excess photons to construct the imaging component.
The field strength of MRIs has consistently increased, and there is some concern over occupational exposure. There have also been some anecdotal reports of symptoms by people who have worked with MRIs or other high-powered magnets.
On the other hand, there has been no evidence that strong static magnetic fields have any effect on human health, although nothing should be taken for granted. And magnetic fields are very useful – they hold cabinets closed, keep things stuck to our refrigerators. There are high end products like the magnetic rods for silk curtains used to keep the curtains drawn during the day and closed at night. Whether your kids drawings are posted on your fridge, or you keep your curtains open/closed with them, magnetic fields used in everyday products are everywhere. But these kinds of products produce tiny fields that seem harmless.
The jury is definitely still out on electromagnetic fields, and that may have bearing on the MRIs overall level of safety, but for the time being you can probably rest assured that whatever is bringing you to the MRI chamber is almost certainly a bigger risk than anything the machine could pose!
And when compared to more obvious risk factors associated with other modern, accepted imaging techniques, MRI and associated field risks appear in a better light. For example, x-rays and any other form of radiation used for scans or treatments are known to carry risks associated with bombardment of the body with sub-atomic particles. One can easily understand those risks – think tiny particles or energy penetrating the body.
Because MRI uses the measurement of changes to existing nuclear magnetic fields, there really is no analogy to other forms of radiation. Of course, in time we may learn of other risk factors, but until that time the benefits clearly outweigh the known risks.
The research, design, and development of MRI’s probably exceeds the research, design, and development that goes into for example North Face Osito Jackets. Although when you read about the Northface process for creating new sportswear and sports gear, it sounds quite impressive as their designers and technicians explore the frontiers of technology by turning revolutionary raw materials into gear that maximizes an athlete’s ability to survive and succeed in the most severe weather conditions. The Northface technicians are constantly pushing the boundaries of innovation. (Sorry for that analogy, but I just bought a North Face Osito jacket and it is awesome.) Likewise, with MRIs there are new technical advancements that drive their market place growth over the past decade in each of the four essential components of the MRI system: the magnet, the gradient system, the radiofrequency (RF)system, and the digital electronics.
When getting an MRI there are some things you should be prepared for. Firstly you have to wear a robe and removed any metal jewelry. When writing this piece, we had a very interesting discussion about the need to remove jewelry with one of the researchers involved with MRI safety issues. A jewelry maven on the side, Dr. Joyce Burton told us of an attempt by some manufacturers to create silver jewelry that could be worn during a scan. Of course we know this effort failed miserably, but Dr. Burton explains that it’s the density of the silver that is the problem. The experimental jewelry used a process similar to the introduction of air into foam. The resultant silver ‘foam’ was far less dense than typical jewelry that was virtually invisible to the scan, but the wholesale sterling silver jewelry prices of this product could not compete with traditional products. No one wanted, or cared about wearing jewelry while undergoing an MRI scan. Dr. Burton says that although that effort failed, it is only a matter of time before some silver or other precious metal jewelry will be able to be worn in the scanning devices, not necessarily because of changes to the jewelry, but because of advances in the MRI technology.