A Brief Guide on MRI Coils and Their Signal-to-Noise Ratios

by | Mar 5, 2021 | MRI

Reading Time: 3 minutes

Medical imaging technologies are significant players in the 21st century, as these have made saving lives possible. Without having to guess what a patient is going through, or what kind of changes are occurring inside their bodies, this makes it a safer method than operating blindly. Compared to the world of yesterday, today’s technologies have made it easier to live healthily and seek assistance for any illnesses. 

While not all illnesses are cured because of their hyper-invasive nature, the fact remains that imaging technologies are some of the most crucial aspects of any healthcare center. Magnetic resonance imaging, known as MRI, is a popular method to have a clear image of a patient’s internal body. It can find abnormal growth patterns and seek out various illnesses and injuries, giving doctors a better way to figure out what needs to be done. The different machines have their respective MRI parts, and the most important one is the coil. Here’s more about the MRI coil and what they do for the imaging process:


MRI Coil Technologies

The MRI coil emits a powerful magnetic field that produces an internal image through the waves passing through a person’s body. Radiologists then read the findings through a computer and provide the results to the person’s physician. The coil is the source of the signal in an MRI machine, and these come in various forms, giving them unique strengths in their scans. 

MRIs produce a reading that’s indicated as a “signal-to-noise” ratio during the scans, which is a measurement of the strength of the reading. Typically, the SNR reading is acquired by the computer, and it’s better to have lower noise levels for a more accurate scan. Noise can be reduced by removing excess items from a patient’s body, especially removing all kinds of metal items and accessories because of the magnetic field produced by the scanner. MRI parts will typically react harshly to metals, which is why the room is only stocked with the scanner and nothing else. 

These scanners typically have different coils that create better readings depending on the body part being scanned. Body scans are better done with radiofrequency coils because of their signal strength that acquires better and more accurate data. Each machine is built differently, and over time, MRI coil repairs will have to be done with the right types for the brand. 


MRI Coils and Their SNR Impacts

Various coil products produce different signals, which all affect the signal-to-noise ratio during a scan. There are traditional machines that still utilize the hard and rigid variants, which are often less accurate because of the bad SNR. Hard coils cannot be shaped against the body, and smaller patients may experience an SNR decrease due to the target’s distance from the coil. New coils are more flexible and allow more accurate readings because of their placement. Since they can be closely wrapped to various regions of the body, the end SNR is better and more improved because the coil is more flexible. 

Other components like the anterior array coil can be useful for spine imaging but are less practical to use because of the challenging set-up for individual scanning. This coil is lighter and has the potential to provide improved imaging because of greater gains towards the SNR rating, plus the adaptive nature to various patient sizes. 



MRI parts are all gears in the bigger machine, but nothing stands out more than the coil that provides the image. With the different variants available now and with future advancements, it’s safe to say that the coming years will see improvements in medical diagnostic imaging technologies. 

DirectMed Parts is a source for high-quality MRI parts in the United States for various scanner brands like Toshiba, GE, Siemens, and many others. Keep your machine in good condition by investing in the best parts, and enjoy proper scanning procedures as a result. Contact us to know more about our parts selection and how we can help with MRI repairs. 


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