Magnetic Resonance Imaging: it’s a thing of medical brilliance. A large tube packed with strong magnets that shoot out radio waves, its ability to safely and effectively visualise tissue has transformed the field of medical diagnosis since its development in the 1970s. An MRI scan can get to almost any part of our bodies, particularly the brain, the spinal cord, breasts and other internal organs.
One part of the body where the MRI scanner can fall short, however, is the knee. Due to the size of the scanner, certain key components of the knee are tricky to pick out on current MRI technology. And due to the effectiveness of MRI scans in other, more life-threatening conditions, people in need of a knee scan are being put at the end of a long waiting list.
However, that wait could be getting shorter in future, if a research study recently conducted by scientists at Imperial College London bears fruit. They’ve produced a prototype of a miniature MRI scanner designed to be fitted around the knee. And not only does it work better on the knee than its larger counterpart, but it’s also small enough to be based or rented out to your local clinic or even your GP surgery.
Why do standard MRI scanners find it hard to examine knees?
While an MRI scan can easily pick out the components of other parts of the body, it’s a lot trickier with the knee. And that’s because of the way water molecules are arranged in our tendons, ligaments and meniscus. Those structures are mainly made from collagen, a protein which knits itself into fibres.
As those fibres cling onto water molecules extremely tightly, they show up as blocks of black on a standard MRI scan, giving off the impression that there is more fluid around the knee than there actually is, which makes it tough for medical staff to make a call on the actual state of the area.
Introducing the Magic Angle
Due to the reduced size of the prototype scanner, however, the research team claim it can deploy what they call a ‘magic angle’ – the ability to come at the joint from a whole new perspective which produces a sharper, brighter image. This is achieved by a specially-designed magnet, which can whizz around the knee area and help build up a fuller picture – something that a standard scanner simply can’t do.
The prototype scanner has already been tested out on goats and dogs (as both animals can suffer knee injuries similar to those found in humans), and the results were extremely positive. Now the research team are looking forward to trying it out on humans within the year – and if all goes well, potential knee problems could well be picked up on without a trip to the hospital, which could take a lot of work and expense out of the NHS and help doctors come to a swifter and more accurate knee injury diagnosis.