Radio diagnosis

Researchers at Imperial College London have developed a prototype mini MRI scanner that fits around a patient’s leg. The team say the device which uses so-called ‘magic angle’ effect could potentially help diagnose knee injuries more quickly; and more accurately. In a proof-of-concept study using animal knees; the results suggest the technology  use to show all the structures of the knee.

Prototype mini MRI scanner

The scientists say the device (which looks like a large metal ring through which a patient places their leg); could help diagnose conditions such as anterior cruciate ligament injuries particularly common among footballers. Furthermore; the small size of the device could enable it to be used in local clinics and even GP surgeries, potentially reducing NHS waiting times for MRI scans. The research is find by the National Institute for Health Research.

Currently, key components of the knee joints such as ligaments and tendons are difficult to see in detail in the MRI scans, explains Dr. Karyn Chappell; a researcher and radiographer from Imperial’s MSK Lab: “Knee injuries affect millions of peopleand MRI scans are crucial to diagnosing the problem; leading to quick and effective treatment.

Knee injuries affect

However we currently face two problems: connective tissue in the knee is unclear on MRI scans, and people are waiting a long time for a scan.” Dr. Chappell added: “This can cause particular problems for women; as they are at greater risk of anterior cruciate ligament injuries. The reasons for this are unclear; but it could be link to hormones such as oestrogen making ligaments more elastic, leading to more joint injuries.”

Knee injuries commonly affect one of three areas: the tendons (which attach muscle to bone); the meniscus (a cushioning pad of cartilage that prevents the bones of the joints rubbing together), or the ligaments (tough bands of connective tissue that hold bones in a joint together).

Particular problems for women

Following knee injury a doctor may refer a patient for a MRI scan to help establish which part of the joint is injure. MRI scans use a combination of radio waves and strong magnets to ‘flip’ water molecules in the body. The water molecules send out a signal, which creates an image.

However; tendons, ligaments and meniscus are not usually visible with MRI; due to the way water molecules are arranged in these structures, explains Dr. Karyn Chappell. “These structures are normally black on an MRI scan—they simply don’t produce much signal that can be detected by the machine to create the image. This is because they are made mostly of the protein collagen, arranged as fibres.