What is an MRI scan and how does it work?
MRI is an imaging diagnostic procedure that uses magnetic field to take detailed images of the human body.
The magnetic field generated by the device converts the energy changes in the body into a high-resolution, three-dimensional image by a high-performance computer.
At Medicover Diagnostic Center, we use equipment that works with a closed but extremely short tube. It is 10 centimetres wider than average and its diameter is 70 cm, thus helping reduce the feeling of confinement.
In Hungary, MRI machines with a strength of 0.5-1.5 Tesla are most often used, which is 150 times stronger than an average fridge magnet. The strength of the magnet affects the quality of the images, the stronger it is, the sharper the image of the organs and tissues examined is.
The 1.5 Tesla Siemens Magnetom Aera device, which has been operating in our diagnostic center since 2016, is excellent for making detailed, high-resolution images and for making an accurate diagnosis.
When is an MRI scan necessary?
MRI is a painless and side-effect-free examination, which has no harmful effects on the human body, but still gives a precise picture of the examined area and organ, thus facilitating the accurate diagnosis.
Due to its high resolution, it is excellent for exploring central nervous system (brain, spinal cord, pituitary MRI) problems, diagnosing stroke, heart and vascular problems, thrombosis, examining spinal (neck, back, lumbar) and joint (shoulder, elbow, hip, knee, ankle), chest, abdominal soft tissues (muscles, blood vessels, adipose tissue, connective tissue) and abdomen and pelvis, sacrum (hip and sacrum), and breast and cervical soft tissues (thyroid, parathyroid, lymph nodes, salivary glands, blood vessels, muscles) problems and to diagnose ocular lesions (orbit MRI). Our diagnostic center also offers full body MRI examination. MRI scan with contrast agent is performed only with a written medical recommendation.
How do I prepare for the test?
The examination does not require special preparation. However, if an MRI scan with contrast agent is needed, it is important that you arrive with an empty stomach, therefore do not eat for 6 hours before the appointment.
Examination with contrast agent requires a laboratory test for kidney function not older than 1 month, which also includes testing for keratin and urea levels, which show kidney function. If you are unable to present a laboratory result, it is possible, for an additional fee, to perform a rapid test before the scan, which is a blood sample taken from a fingertip.
Prior to the examination, at the time of booking, our colleague will interview you in detail about any metal that may be present in your body, and other circumstances, as well as provide accurate information about the documents required for the examination (e.g. medical recommendation).
What happens during an MRI scan?
- Following the pre-examination orientation, the operator enters the MRI examination room and asks you to be located on the examination bed
- The operator adjusts the body position required for the test (the test is usually performed in a supine position), places the necessary coils, and then the examination bed lifts you into the magnetic tube
- It is important that you stay still during certain stages of the examination, you can only change your body position with the permission of the operator
- The examination takes an average of 30 minutes (examinations involving more than one body part, such as a whole spine MRI, take longer)
- During the examination, you can continuously communicate with our colleague through the built-in microphone and speaker
- You can reduce the noise of the machine with earplugs
When is a contrast agent needed?
A contrast agent is a paramagnetic (a substance visible to the machine) drug that is injected directly into a vein by our operator. Our colleagues use a certain amount of contrast agent per kilogram of body weight, thus avoiding unnecessary strain on the body.
The contrast agent makes it easier to see the condition of the soft tissues and blood vessels, and we can get a more accurate picture of the location, size and type of a lesion. For some examinations, the non-contrast – native – test is sufficient, while other scans can only be performed with contrast. This is always determined by your treating physician or radiologist.
The administration of the contrast agent is conditional on having a good kidney function value, which can be confirmed by a recent laboratory finding, but it is also possible to perform a creatinine test or eGFR measurement with the help of an MR/CT operator, which happens with a blood sample taken from a fingertip.
What are the benefits of the examination?
- Completely painless
- It does not involve radiation exposure as it is based on magnetic resonance imaging
- No long-term harmful effects to the body
- Can also be used as a screening examination (e.g. whole body MRI)
- It allows you to accurately map the wanted area without invasive intervention
Is the examination risky?
- As a precautionary measure, the examination is not performed during the first trimester of pregnancy (although, according to current scientific opinion, magnetic resonance imaging does not endanger the foetus).
- Magnetic resonance has no harmful effect on human tissues
- The contrast agent can cause a minor allergic reaction, which is extremely rare and easy to treat. To mitigate this type of risk, all of our patients complete a questionnaire in advance that assesses their overall health. Based on this, the operator determines whether the test can be performed.
Are there any side effects of the examination?
Apart from an accidental allergic reaction to the contrast agent, the examination has no side effects. An allergic reaction may occur within 20 minutes of the administration of the contrast agent, therefore in case of malaise, report it immediately to the operator performing the test. Our staff is trained and equipped to deal with these types of side effects.
When can the test not be performed?
- In the first trimester of pregnancy
- In many cases, the test can also be performed if the patient has implanted metal (e.g. a non-magnetizable dental implant).
- Exceptions to this are non-MR compatible metal, implant, prosthesis (pacemaker), orthopaedic metal (screw, plate, nail, wire), implanted joint prosthesis, prosthetic limb, implanted defibrillator, neurostimulator, implanted drug dispenser, vascular implants (e.g. clips, vascular occlusion devices), ear implants, metal foreign body (e.g. bullet, splinter, other electronic implants). Therefore, in case of an implant, implanted metal, prosthesis, please bring a written certificate of its compatibility with MRI examination (certified by the implanting specialist, institution) for the examination itself, which clearly states: the suitability to enter the MRI examination room, to perform the MRI examination and marking the maximum magnetic field strength (1.5 Tesla, 3 Tesla) for the device or implant. Inform the person performing the examination about the implant beforehand.
- Above about 200 kg body weight (depending on abdominal circumference)
- In case of a scan with contrast agent, if the eGFR of the kidney function is below 45 ml/min, the test is not performed
When is the result expected?
The completed scan will be reviewed by the radiologist and the result will be available in our online system after 3 working days.