What is an MRI scan?
An MRI (Magnetic Resonance Imaging) uses a large magnet, radio waves, and a computer to create a detailed, cross-sectional image of internal organs and structures. The scanner generally resembles a large tube with a table in the middle, causing the patient to slide in. MRI is different from CT scans and X-rays because it does not use harmful ionizing radiation.
The development of MRI marks a great milestone for the medical world. Doctors, Scientists, and Researchers can now examine the interior of the human body in great detail using a non-invasive tool.
The following are examples of MRI scanner used:
- Brain and Spinal Cord Disorders
- Tumors, cysts, and other disorders of various parts of the body
- Breast cancer screening for women at high risk for breast cancer
- Joint injuries or abnormalities such as back and knee
- Some types of heart problems
- Diseases of the liver and other abdominal organs
- Evaluation of pelvic pain in women, including fibroids and endometriosis
- Uterine abnormalities are suspected in women undergoing evaluation for infertility
This list is by no means exhaustive. The use of MRI technology is always expanding in scope and use.
How does MRI work?
MRIs use powerful magnets that produce a strong magnetic field that forces protons in the body to match that field. When the patient pulses the radiofrequency current, the protons become excited and unbalanced and are filtered against the attraction of the magnetic field. When the radiofrequency field is turned off, MRI sensors can detect the energy released by proton formation with a magnetic field. The time it takes for protons to redesign with a magnetic field, as well as the amount of energy released, varies depending on the environment and the chemical nature of the molecules. Based on these magnetic properties, doctors can differentiate between different types of tissues.
To obtain an MRI image, the patient must be positioned inside a large magnet and must be very stable so as not to blur the image during the imaging process. Contrast agents (often containing the element gadolinium) can be given intravenously before or during MRI to increase the rate at which protons return with a magnetic field. The faster the protons change, the brighter the image.
Uses of magnetic resonance imaging
MRI scanners are suitable for obtaining images of skeletal parts or soft tissues of the body. They differ from computed tomography (CT) in that they do not use the harmful ionizing radiation of X-rays. The brain, spinal cord, and nerves, as well as muscles, tendons, and ligaments, are clearly visible on MRI compared to normal x-rays and computed tomography; For this reason, MRI is often used to paint knee and shoulder injuries.
In the brain, MRI can detect the difference between white matter and grey matter and can also be used to diagnose aneurysms and tumors. Because MRI does not use X-rays or other radiation, it is an imaging option for diagnosis or treatment, especially when frequent imaging of the brain is needed. However, MRI is more expensive than an X-ray imaging or CT scan.
A special type of MRI is functional magnetic resonance imaging (FMRI), which is used to examine brain structures and determine which areas of the brain are “activated” (take in the most oxygen) during various cognitive functions. It is used to improve the perception of the organization of the brain and provides a new standard for assessing the neurological status and neurosurgical risk.
Are there any risks?
Although MRI does not emit the ionizing radiation found in X-rays and CT images, it does use a strong magnetic field. The magnetic field extends beyond the machine and exerts very powerful forces on iron, some steels, and other magnetic objects. It was strong enough to throw a wheelchair across the room. Patients should inform their physician of any medical or implant before the MRI scan. MRI image of the upper body and head of a person.
When performing an MRI, the following should be considered:
- Those with implants, especially those with iron, should avoid pacemakers, vagus nerve stimulators, implanted cardioverter defibrillators, circuit recorders, insulin pumps, cochlear implants, deep brain stimuli, and capsule endoscopy.
- Noise: Typically loud clicking and beeping noise, as well as sound intensities of up to 120 decibels in some MRI scanners, may require special ear protection.
- Nerve stimulation: A twisted sensation sometimes comes from rapidly changing areas on magnetic resonance imaging.
- Contrast agents: Patients with severe kidney failure who require dialysis are more likely to develop a rare but serious condition called nephrogenic systemic fibrosis, which may be associated with the use of certain gadolinium-containing agents, such as gadodiamide and others.
Although the causal link has not been established, current guidelines in the United States recommend that dialysis patients receive gadolinium agents only when necessary and that dialysis removes the agent from the body as soon as possible after the scan.
Although pregnancy does not affect the fetus, it is recommended to avoid MRIs during the first trimester of pregnancy, when the organs of the fetus are formed and if contrast agents are used, the fetus can enter the bloodstream.
- Claustrophobia: People with mild claustrophobia find it difficult to tolerate longer scan times inside the machine. The introduction to the machine and the process, as well as the visualization techniques, provide mechanisms for anaesthetized and anaesthetized patients to overcome their discomfort. Additional coping mechanisms include listening to music or watching a video or movie, closing or closing your eyes, and holding down the panic button.
An open MRI is a machine that opens sideways rather than a tube closed at one end, so it does not surround the patient. It was developed to meet the needs of patients who are uncomfortable with the narrow tunnel and sounds of a traditional MRI and for patients whose size or weight makes a traditional MRI seem impossible. New open MRI technology provides high-quality images for most people for all types of exams.
Preparation for MRI
Before an MRI, very little preparation is required. Upon arrival at the hospital, doctors may ask the patient to change into a gown. Since magnets are used, there are no metallic objects in the scanner. The doctor will ask the patient to remove any jewellery or metal accessories that may interfere with the machine.
A person may not have a magnetic resonance imaging if they have metals such as bullets, sharp objects, or other metallic foreign objects inside their body. It can also include medical devices such as cochlear implants, aneurysm clips, and pacemakers. People anxious or nervous about enclosed spaces should inform their doctor. Medications can often be given before the magnetic resonance imaging to make the procedure more comfortable.
Sometimes patients are given an injection of intravenous (IV) contrast fluid to improve the visibility of a specific tissue related to the scan. The radiologist, a doctor who specializes in medical imaging, will then talk with the person through the magnetic resonance imaging scan procedure and answer any questions you may have about the procedure.
Once the patient enters the scanning room, the doctor helps them lie down on the scanner table. The staff will be as comfortable as possible by providing you with blankets or cushions. Earplugs or headphones are provided to block out loud noises from the scanner. The latter is popular with children because they can listen to music to calm anxiety during the process.
During the MRI
Once in the scanner, the MRI technician communicates with the patient via intercom to ensure that they are comfortable. They do not start the scan until the patient is ready. During the scan, it is very necessary to be still. Any movement can alter images as if the camera is trying to capture an image of a moving object.
Loud choking sounds are coming from the scanner. This is absolutely normal. Depending on the images, the person may sometimes need to hold their breath. If the patient feels uncomfortable during the procedure, they can speak to the MRI technician over the intercom and request that the scan stop.
After the magnetic resonance imaging
After the scan, the radiologist will review the images and see if anything else is needed. If the radiologist is satisfied, the patient can go home. The radiologist prepares a report for the requesting physician. Typically, patients are asked to make an appointment with their doctor to discuss the results.