Considering that during the MR scan you enter the magnetic field which can attract metal objects from you, your clothes or jewelry, you have to take every metal object off the body or take off your clothes and wear a cloak and slippers which will be handed to you by our radiological personnel.
Those metal objects include:
Also, you have to inform the radiological personnel if you have any metal objects in your body (pacemaker, cochlear hearing aid, postoperative clips, artificial joint, osteosynthetic material after a surgical fracture treatment, stents in blood vessels, artificial heart valves, metal debris and other) because there can cause disruptions during the MR scan, and some of them are contraindications for the procedure. Some of the surgically implanted objects do not cause MR disruptions, but you have to get a paper confirmation from your surgeon.
Instructions for taking food and drinks before the MR scan depend on the type of examination to which you are instructed to go to. MR scans of the musculoskeletal system do not require any special attention regarding intake of food and drink.
You can follow your routine daily rhythm of taking medications before the MR scan.
Some of the MR scans can require the application of a contrast agents intravenously or in the joint itself. The radiological personnel will ask you about your allergies to drugs, food or anything other. Contrast agents which are used for MR scans contain gadolinium and mostly do not cause allergic reactions.
Furthermore, you will be asked about the existence of some other health issues, primarily the ones which affect the function of the liver and kidneys.
Women in reproductive age need to inform the radiological personnel about a potential pregnancy. Although MR is being used for many years (since the 1980s), no harmful effects on the women or fetus have been reported. However, due to the high sensibility of the fetus, MR is not recommended in the first three months of pregnancy and later if there is a clear medical indication.
If you are claustrophobic (fear of being in a small space), you can ask your physician for a mild sedation medication to feel more comfortable during the procedure.
What does MR equipment look like for doing a scan of the musculoskeletal system?
The MR machine looks like a tunnel. During the scan, the patient is lying on the table which is retracted in the tunnel of the machine at various depths depending on the part of the body undergoing the scan. Sometimes coils are put around the part of the body undergoing the scan (e.g. around the head and neck) which are necessary for the MR scan.
Workstation with a computer from which the MR machine is controlled is in a separate room.
How does the MR machine work?
Unlike X-ray scans or computerized tomography, MR does not use ionizing radiation to create an image.
During MR scans, the body is located in a strong magnetic field which affects all tissue cells, i.e. its protons and gets them in a specific order. Radio frequent waves from the machine carry the energy to those protons and removes them from a balanced state. After the radio frequent wave stops, the protons return to a balanced state and give away the excess of energy to the environment. That energy is received by the MR machine, and the computer of the machine transforms it into a picture.
What does MR of the musculoskeletal system look like?
During the scan, the patient is lying on a moveable table of the MR machine. To make the body stable, different pillows and tapes are used. The provide additional calmness during the scan. To minimize the noise during the scan, the patient will get headphones or ear plugs.
When taking joint scans, additional coils are used that are put around the joint itself. They receive and transmit the signal.
During the examination, the movable table on which the patient is lying is retracted in the tunnel pf the MR machine in such a way the part of the body undergoing the scan is located in the middle of the tunnel. The radiological personnel leave the room because the workstation with the computer that controls the MR machine is located in a separate room.
MR scanning is composed of multiple short sequences during which the MR machine produces noise. Because of that, the patient will get headphones or ear plugs.
During the examination, the patient needs to remain still, because any movement reduces the quality of the picture and requires repetition of parts of the scan.
Sometimes it is necessary to apply a contrast matter intravenously or in the joint itself if MR artrography is being used.
What to expect during and after the MR scan?
The MR can is painless if there is no need to apply any contrast matter intravenously or in the joint itself.
Considering that the scanned body part is located in the tunnel of the MR machine, the procedure can be uncomfortable in patients who are claustrophobic (fear of being in a small space). These patients should take a mild sedation medication prior to the MR scan to feel more comfortable during the procedure.
During the scan the MR machine produces noise. Because of that, the patient will get headphones or ear plugs.
MR scanning is composed of multiple short sequences which repeat one after the other. You have to remain completely still during the scan.
The patient is alone in the room during the MR scan, but the radiological personnel is monitoring the patient at all times through a window and communicates with him/her via an interphone. During the scan, a person from his/her escort can stay with the patient in the room.
If an application of the contrast matter is necessary, it is being injected intravenously through a vein on the arm (in the elbow, forearm or the hand) or in the joint. It is recommended for women who breastfeed to not do it 36 to 48h after the application of the contrast matter.
What are the advantages, and what are the risks of MR scans?
MR is a radiological imaging procedure which does not use ionizing radiation to create the image.
Good imaging of soft tissue structures of the body (muscles, ligaments, tendons, nerves)
Better differentiation between normal and pathological tissue on MR scans than other imaging methods (X-rays, CT, US).
The contrast matter being used on MR scans causes a significantly smaller number of allergic reactions in comparison to other radiological contrast matters which are used in X-ray and CT scans.
MR enables the visualization to bone fractures when they are not yes visible on X-ray scans (especially in cases of stress fractures), and bone contusions.
Because of the precise imaging of soft tissue damage, it is an indispensable method in the examination of sport injuries.
In most cases, the MR scan does not pose any risks for most of the patients if the required precautions are applied.
If the patient is sedated during the examination, it is necessary to monitor his/her status during the procedure and shortly after it.
A strong magnetic field can affect metal objects in the body.
The is a very small risk of an allergic reaction to contrast matters which are used during an MR scan. If they appear, they are usually mild.
Nephrogenic systemic fibrosis can appear when applying high doses of some contrast matters in MR patients with significantly reduced kidney function.
Safety during MR scans
By following usual safety precautions during the MR scan and that there is no scientific evidence about MR being harmful for patients, MR imaging is considered a safe radiological diagnostic method.
Pregnancy and MR scans
What are the limitations of MR scans of the musculoskeletal system?
High quality of MR scans will be achieved only if the part of the body undergoing the scan in completely still during the scan. If the patient is restless, afraid or is suffering pain, being still during the scan will be a problem.
An adipose patient will have difficulties entering the MR tunnel because of his/her volume and weight.
Any metal objects in the body or patient movement during the MR scan will create a poor-quality MR image.
MR scan in general is not the method of choice for acutely afflicted patients that require monitoring of vital functions and life support equipment considering that such equipment is usually not compatible with the magnetic field (the magnetic field attracts it). The MR scan itself takes longer than other radiological methods (X-ray, CT).
Although there is no scientific proof that MR is harmful for the fetus, it is advisable that MR during pregnancy is done only if there is a clear medical indication.
MR cannot always give a clear pathohistological characterization of the pathological change.
The whole MR scan takes around 30 minutes.