Orthopedics and Traumatology Specialist Op. Dr. Ali Yılmaz answered many curious questions, about how Magnetic Resonance (MR) Imaging works, whether it is harmful, and in which cases MR should not be withdrawn.
What is Magnetic Resonance Imaging (MR) and What Does It Do?
It is the most advanced and highest level imaging method among imaging methods in all fields of medicine.
One of the most important features is that it works without any harmful factors and x-ray to the body. The device, which provides a strong magnet environment, creates images by recording and evaluating the movements of hydrogen and neutron atoms, which are abundant in the water and adipose tissue in the body thanks to radio frequencies and creates images. All tissues and organs in the body; pictures are taken and recorded in detail by dividing into sections and looking from different directions. It has been used in medicine for nearly 45 years and has no reported harmful effects.
In which cases should MR be used?
All areas of medicine need imaging of MR. However, the branches of medicine that need the MR examination the most are; Orthopedics and Traumatology dealing with musculoskeletal problems, Neurology and Neurosurgery dealing with diseases of the cerebrospinal system. MR device with high magnet power is required in cardiovascular diseases. It has been one of the two methods that have revolutionized the diagnosis and treatment of musculoskeletal diseases and has made great progress. MR is not done for diagnostic purposes only. It is also very important for differential diagnosis, identifying concomitant problems, planning therapy and predicting the past and future of the current problem.
Before taking MR, the doctor of the relevant branch always listens to the patient, examines it and performs first-line routine examinations. Then he sends the patient for an MR examination by writing a preliminary diagnosis or the reason and thought of why he had an MR. The physician, radiologist and MR technician who made the request of MR should work in cooperation. For accurate diagnosis, the patient’s complaint, examination findings, routine examinations before MR and MR images should be compatible with each other.
In almost all diseases and injuries of the musculoskeletal system; MR examination may be necessary both in early diagnosis and diagnosis, in the treatment plan and in determining the future of the current problem. MR can be performed for many conditions such as detection of all joint problems, diagnosis and treatment planning of ligament and muscle injuries due to sports injury, detection of hidden fractures and osteoporosis in tumors, monitoring and evaluation of repaired tissues after surgery.
In which situations can a person not enter the MR device and an MR prompt should not be made?
Those with metallic vascular clips in the head, pacemakers, automatic rhythm-regulating pacemakers (automatic defibrillators and biostimulators), those with some continuous medication and implanted devices (infusion device), those with internal hearing aids and those with metallic foreign bodies can never enter MR device. Those who have a heart valve prosthesis can safely enter the MR device.
In the first 3 months of pregnancy, middle ear prosthesis and penis prosthesis are conditions that should be considered and should not be withdrawn unless it is mandatory and are known as partial obstacles to MR attraction. In general, patients with internal orthopedic devices and prostheses can safely enter the MR device. However, in the presence of device and prosthesis containing iron elements, MR images may be distorted or blurred. In the presence of metal orthopedic device placed externally and not compatible with MR, the person cannot enter the MR device.
Still the safest approach; regardless of the medical branch, it is the fact that a person who has a metal device on his body informs his / her physician about the current situation and confirms whether the device is compatible with MR by talking to the relevant company representative.
What Should Be Done Before Coming To MR?
If there is no shooting under anesthesia, there is no need for starvation, prior medication or urine compression as in ultrasound. However, if it is necessary to shoot under anesthesia for babies or children, or those who have fear of indoor space, it may be necessary to prepare as instructed by your doctor.
How to Take MR and What to Consider While Shooting?
The person entering the MR device should be dressed with an MR apron. No small or large metal objects should be on the patient. For example necklace, earring, belt, key chain etc. During shooting, motion should be avoided so that there is no image interference, especially the area to be shot. In some shots, it may be necessary to hold the breath for a while with the command of the technician.
How does MR used?
After the patient is placed into the MR device, the device is set in the area to be examined with MR, which is called a specially designed coil and has an antenna feature. There are coil devices specific to each region. Coil usage is extremely important for image creation and image quality. Then, the technician ensures that the place to be shot remains stable by making adjustments that fit exactly inside the device. Then the shooting begins. The shooting time varies depending on the magnet power of the MR device, the update status, the number of shots, the condition of the area to be shot and the disease, but it may take 15-45 minutes. High magnet power (1 tesla and higher magnet power is accepted) With MR devices, the shooting time is significantly short.
What Is The Tesla Power Of MR Device And What Does It Do?
Tesla describes the magnetic power of the MR device. High magnetic field above 1 tesla is defined as low magnetic field below 0.3 tesla. While low magnetic field is created in open MR devices, high magnetic field is created in closed MR devices.
MR device with low tesla power; open MR shaped and smaller size. The problem of moving and taking up space is less. It is cheap. The most important advantage is; patients with fear of confined space and overweight easily adapt. MR device with high tesla power; known as closed MR. It has a larger size, open-ended cylinder shape and is expensive. The most important disadvantage is in the form of closed MR, and it is a problem for patients with fear of closed space.
In medical terms, MR devices with closed or high magnetic fields have important advantages in terms of image quality and detail. The Tesla high MR device makes it possible to examine tissues and organs in thinner sections. Small areas; (jaw joint, hand, foot – ankle, heart, kidney, internal organs etc.) provides detailed visualization. Shooting is done in a shorter time. In terms of image quality; It has an oil suppression feature, which is a very important feature in diseased and normal tissue separation. MR device designs in the form of high tesla power and open MR are available in the future, and device development efforts and development that combine the advantages of open and closed MR continue. Today, there are 3 tesla MR devices and these devices are especially important in the diagnosis and monitoring of nervous system and cardiovascular diseases.
What are the advantages of MR?
MR device works without using any harmful agent or drugs or radiation. With this aspect, it provides a great advantage to computed tomography and has replaced the computed tomography device as an examination method in the diagnosis of most problems. Thanks to MR devices and computer programs with high tesla power, even millimetric problems of tissues and organs can be diagnosed. Detailed pictures of the internal structures of organs and tissues are taken. Again, with special shots, it is possible to examine tissues and organs even at an invisible biochemical level. It is not only important with the diagnosis and early diagnosis of the patients, but also in the differential diagnosis, determining the accompanying problems, planning the treatment, monitoring and determining the future disease and the consequences of the current disease.
Are there any disadvantages to Emar?
MR has no negative impact on human health. It has been used for about 45 years and there are no reported adverse cases. If the shooting rules mentioned above are followed (such as entering the MR room with metal objects), possible accidents do not occur. Its main disadvantage is that it is a relatively expensive method. Shooting is difficult in people with fear of confined spaces and people with high weight problems. In the future, it will be the solution of these problems with MR devices that are open and have high magnetic power.
Birsen Dokgoz, M.D.