Is MR Harmful? When should it be done?
(Update: ) - general subjects
It is known as “magnetic resonance imaging MRI” in Latin, Magnetic Resonance Imaging (MRI) in Turkish, nuclear magnetic resonance imaging or magnetic resonance tomography. It is called MR or Emar for short among the people. So Is MR Harmful? MRI is a diagnostic tool used for imaging the body tissues and organs of living things and diagnosing diseases. With a high level of magnetism, living tissue is displayed by the reflection method.
This process, commonly known as MRI, is actually nuclear magnetic resonance imaging. It creates images according to the densities and movements of the hydrogen atoms in the tissue. Radiation (X-ray) is not used in MR, instead, the proton in the nuclei of hydrogen atoms in the body is excited by the magnetic field. The signals reaching the receivers are transformed into black and white images with computer analysis (in Perfusion imaging)
results can be colored) converted. The magnetic field used for this purpose is in the range of 1 - 1,5 Tesla. Sometimes the question may arise, how much tesla is good for MRI? There is no direct connection between an excess of tesla and an efficient shot, and an excess of tesla may also mean an increase in the side-effect. Today, MRIs up to 5,6,7,8,9,10 tes are available in developing countries, but 1.5 T and above devices are used for very special cases and research purposes.
Currently, MRI is used especially for imaging soft tissues. It is frequently used in the diagnosis of central nervous system (brain and spinal cord) diseases, athlete injuries, musculoskeletal system, especially in the detection of disorders such as meniscus and herniated disc, as well as in the evaluation of all kinds of neurological diseases.
Is MR Harmful?
There is no proven harm of MR imaging on living organisms so far. This includes pregnant women; However, MRI is not recommended in the first trimester (1st trimester) when organ development takes place. People with metal interaction, carrying magnets or metal prostheses in their body, using pacemakers, having foreign objects in the eye, suffering from gunshot wounds (most of them are incompatible metals) or having permanent tattoos are considered undesirable (life-threatening) to enter the MRI device.
The magnetic resonance imaging time varies depending on the area examined, the number of regions, and the pre-diagnosis made, and it takes 15 - 75 minutes. It may take between. In addition, if necessary, contrast agent (medicated) imaging is performed using IV (intravenous) during the examination.
There are different types of magnetic resonance imaging such as Functional MRI, Diffusion-Perfusion Weighted MRI, MR Spectroscopy.
What is Magnetic Resonance Angiography (MRA)?
MR angiography is an MR study in which the vessels in the body are imaged. It has been used quite frequently in recent years in the diagnosis of vascular diseases using MR technology. Large main veins can be easily visualized without drug administration. However, by using special drugs called Gadolinium, the image quality increases significantly and fine details of vascular structures can be displayed.
The most important advantage is that the risk of allergic reactions due to contrast agents used in catheter and CT angiography is very low. In some cases, the disadvantage is that it creates false results as a result of image pollution, which is called artifact. Examination time and cost is lower than other angiography methods.
How is Magnetic Resonance Angiography performed?
The patient is placed on a special table placed inside the MRI scanner. A standard method consists of imaging sequences ranging in number from two to six, each lasting two to ten minutes. Each sequence provides a specific image orientation and a varying degree of image contrast and clarity. Gadolinium is administered through a vein during one of the sequences if contrast agent is required. This drug allows the veins to shine and better distinguish them from surrounding tissues.
Most Used Regions:
- Cerebral MRA: MR angiography of brain vessels
- Carotid and Vertebral MRA: Visualization of the main vessels from the neck to the brain
- Aorta MRA: MR angiography of the main vessel coming out of the heart and returning from the chest cavity to the abdomen and carrying blood to the body.
- Limb MRA: MR angiography of arm and leg vessels
- Renal MRA: MR angiography of kidney vessels
MRCP is an inexpensive, non-invasive and non-ionizing examination that provides high-signal imaging of stagnant fluids such as bile and pancreatic fluid compared to surrounding soft tissues. The application is performed after 6-8 hours of full fasting and takes 2,5-3 minutes. With MRCP (MRCP), stenosis and enlargements in the bile ducts and pancreatic duct and their causes (stone, bile sludge, tumor, etc.) can be revealed.