Diagnostics of choice – MRT
With the help of magnetic resonance imaging (or magnetic resonance tomography), the shape and extent of a meniscus tear can be assessed more precisely. The principle of MRI is based on the magnetic properties of individual atomic nuclei in our body, each of which has a certain characteristic intrinsic angular momentum. The exact function is very complex – in simple terms, a computer can record and evaluate the impulses so that a three-dimensional image is ultimately produced.
The MRI thus provides a 3D imaging method that can display meniscus tears in any spatial plane. The MRI image offers the possibility of different image contrasts through the use of magnetic fields and radio waves. Depending on which tissue can be assessed, the MRI image is weighted.
The basis for this are the hydrogen atoms that are found everywhere in our body, but with different densities and often in different organs. Thus, in some muscle or meniscus weightings, muscles or menisci appear darker and fluids lighter (T2-weighted image), while in other images, fat-rich structures appear lighter (T1-weighted image). With the help of this principle of different contrasts, different structures can be easily distinguished from each other on an MRI image.
In general, MRI offers the advantage that there is no radiation exposure (ionizing radiation) compared to X-rays. It is also very well suited for imaging soft tissue, including the menisci and other structures (ligaments, cartilage and synovial membrane) of the knee joint, since even the smallest lesions and irritations can be detected. MRI is therefore considered the gold standard in the diagnosis of meniscus tears.
Procedure MRT for meniscus tear
Nowadays, MRI is performed by radiologists and medical-technical radiology assistants (MTRA) either still in the clinic itself or, in the case of less acute concerns, in radiological ones. It is very important to inform the patient in advance about the subsequent examination, as possible contraindications can be asked for by the physician in such a conversation.As already mentioned, an MRI works with magnetic fields, among other things, so that metallic objects can be attracted and heated by the device. This poses a potential risk of injury to the patient, but it can also seriously damage the MRI machine itself.
If patients wear a pacemaker, for example, they are not allowed to undergo an MRI examination. Jewelry, glasses, watches and other metallic objects must be removed beforehand. During the examination, the radiologist and the MTRA leave the room in which the MRI machine is located.
However, they can monitor the patient through a glass window from a separate room. In addition, there is an intercom system for mutual communication and, for emergencies, a safety bell that can be operated by the patient. Often patients have claustrophobia because the device is very narrow and narrow.
For clarification of a torn meniscus, however, the head is usually placed outside. It is important to know, however, that the MRI examination is completely painless and that you usually do not notice anything. The only thing you will hear are the loud noises coming from the MRI machine (“knocking”/”clicking”/”rattling”). You can wear ear muffs or headphones with music for attenuation and distraction. In the case of a meniscus tear, the procedure does not take quite as long as in more complicated or extensive analyses.
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