By Naomi Fried, Staff Writer
If you have ever had a Magnetic Resonance Imaging (MRI) scan, you know how big the machine is. It will usually take up the whole room; the massive machine is seemingly unportable and very expensive. MRI may be used to diagnose or monitor treatment for a variety of conditions within the brain, chest, abdomen, and pelvis. Out of all imaging techniques, MRI images are among the most detailed images available in the medical industry today. Unlike other imaging techniques, they are completely safe and don’t give off any radiation.
When patients exhibit stroke symptoms, doctors have to decide as quickly as possible if the symptoms are caused by a clot that can be dissolved with blood thinners or if there is a bleed in the brain that has to be treated with surgery. An MRI scan can help determine this by detecting if there is bleeding in the brain. This method of diagnosis is very accurate but the main challenge is MRI availability. MRI machines are among the most expensive imaging devices and can cost anywhere between 1 to 3 million dollars for just one machine.
Additionally, there are high maintenance costs associated with the machine, and the machines require great amounts of power to operate. The machines are very large and can’t be moved on a regular basis. All these factors contribute to the low availability of the machines and the long waiting times of patients. Due to these reasons, MRI scans are challenging to obtain during a medical emergency.
A new invention has made MRI more available: Swoop, the portable MRI imaging system created by Hyperfine.
The portable MRI machine is a new product that does not have the disadvantages that the traditional MRI machine has; it is small, portable, and inexpensive. Scans can be made while a patient is in their bed. This can help alleviate some of the anxiety and fear associated with getting an MRI. Because it is an open machine, there is also less of a concern for people who suffer from claustrophobia. The machine can be transported to different areas so that people with less access to care can also benefit from it. Additionally, the low cost and high availability will allow for frequent monitoring over long term periods of chronic diseases. Until now, MRI was used mainly for diagnosis and monitoring over long time intervals, and this new technology can be used more frequently for more rapid information.
What is different about portable MRI technology that allows for these benefits? To answer this, one needs to understand how an MRI machine works.
An MRI machine records images of the soft tissue by producing magnetic fields and radio waves into its surroundings. Our body is mainly composed of water. Water molecules have one oxygen atom and two hydrogen atoms. The hydrogen ions are also known as protons. Water is polar, and when introduced to a magnetic field, high-energy water molecules will start spinning in alignment with the magnetic field. Some water molecules are lower in energy and will not spin. This is where the radio frequency comes in: the radio frequency will give the low-energy water molecules the energy they need to spin at the same speed as the rest of the water molecules. Once the radio frequency is introduced, all water molecules will spin along with the magnetic field. The radio frequency is then stopped. The low-energy water molecules will release the energy they absorbed and return to their original position. This return movement releases energy which can then be translated into an image that radiologists use to detect abnormalities.
Most MRI machines are closed machines, and they operate at a high magnetic field. The strength of a magnetic field is quantified in tesla (T) measurements. A strong (high) magnetic field is between 1.0T and 3.0T. There are also open MRI machines that have a lower magnetic field and operate at between 0.2-0.35T. The stronger the magnetic field, the higher the image quality, and the faster the image can be obtained. Closed MRI machines have a higher magnetic field, and their structure allows for less magnetic frequency to escape. Open MRI machines will allow more magnetic energy to escape, and, therefore, an image of lesser quality will be obtained.
The portable MRI machine operates as an open MRI machine. It has a low magnetic field, which could raise concerns regarding the images quality. These concerns can be disproven by the promising results of the Yale New Haven study. The study, which was conducted during the COVID-19 pandemic, differentiated between patients with COVID-19, and patients without COVID-19. Out of the 30 patients who had neurological abnormalities detected by conventional MRIs, 29 of those patients’ abnormal findings were detected by portable MRIs. This shows a 97% accuracy with portable MRI in comparison to conventional MRI. The study also discusses the accuracy in COVID-19 patients. In patients with COVID-19, out of 20 patients who were scanned with conventional MRIs, eleven of these patients were also scanned with the portable MRI and the findings were found to be in agreement with conventional MRI studies. The study’s findings were as follows: “This experience demonstrates that low-field, portable MRI can be deployed successfully into intensive care settings. This approach may hold promise for portable assessment of neurological injury in other scenarios, including the emergency department, mobile stroke units, and resource-limited environments.”
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Sources:
https://jamanetwork.com/journals/jamaneurology/fullarticle/2769858
https://www.sciencemuseum.org.uk/objects-and-stories/medicine/visualising-body
https://www.ajronline.org/doi/10.2214/ajr.181.5.1811211