Dorothy FarrarMagnetic resonance imaging (MRI)
Magnetic resonance imaging (MRI) or magnetic resonance imaging is used in medical diagnostics to visualize organs and the structure and function of tissues.
What is magnetic resonance imaging (MRI)?
This imaging method of MRI is based on the physical principle of nuclear magnetic resonance, which is where the name magnetic resonance imaging comes from.
It can be used to generate cross-sectional images of the body, which are important for an assessment of the organs and many pathological organ changes (see figure, image of the MRI of a human head).
The examined body areas can be displayed two- or three-dimensionally. In contrast to the harmful X-rays, which are used in computed tomography or X-rays, this application method uses harmless magnetic fields and radio waves.
This strong magnetic field, which is located in the nuclear spitomograph, aligns the atomic nuclei in the human body. Through this alignment, the atomic nuclei reach a more energetic state than before.
The magnetic resonance tomograph also emits radiation in the radio frequency range and thus these atomic nuclei then vibrate. When this signal is switched off again, the atomic nuclei return to the lower-energy state, causing them to emit signals.
These can then be measured by certain antennas. From these measured signals, computers can calculate a cross-sectional image through the body.
Application
MRI can be used for different symptoms and clinical pictures. The different layers of the body can be distinguished so well because the individual types of tissue differ greatly in their content of hydrogen.
Soft tissues, such as the brain or internal organs, are particularly good to represent, as they contain a lot of hydrogen. Inflammations and tumors can also be detected very well with this method, as the hydrogen content here differs greatly from healthy tissue.
It is more difficult with bones because they contain very little hydrogen. Sometimes it is necessary to work with contrast agents in order to better delineate unknown structures (such as tumors).
Process and costs
During the examination, the patient is pushed into the tube of the MRI (see figure). It is important that he lies still so that the recording is not disturbed. To support this, patients are secured with pillows of various sizes.
The duration of the examination depends heavily on the region to be examined and is 10-30 minutes for the examination of the head. The examination of the lumbar vertebrae takes about 20 minutes. During the examination, the patient is always connected to the examining doctor by a bell, so that he can end the examination at any time. The price for an MRI is between 140 and 1200 euros, depending on the complexity of the examination and the organs to be examined.
Risks, dangers and side effects
An MRI should not be done if metal on or in the body cannot be removed first. This leads to side effects and image disturbances. It can even happen that certain metal foreign bodies, such as iron splinters in the brain or in the eye, become dangerous due to the displacement caused.
The modern titanium metal implant is not normally a problem. Pacemakers could also be damaged by the alternating magnetic fields.
Women who are 1-13 weeks pregnant should also refrain from an MRI. Large tattoos can cause skin burns and large piercings should also be removed. Patients suffering from Claustrophobia (fear of claustrophobia) can only be examined under anesthesia.
Hello and welcome to my Health Guide & Encyclopedia! My name is Dorothy Farrar, and I'm the founder and main author of this platform.
My passion for health and wellness started at a young age when I became interested in the connection between the food we eat and the way we feel. This fascination led me to study nutrition and dietetics in college, where I learned about the importance of a balanced diet and the impact of various nutrients on the body.