What is MRI?

What is MRI?

Magnetic Resonance Imaging (MRI) is a medical diagnostic tool that generates lifelike images of various parts of the body by using a strong magnetic field and radio frequency waves to send and receive signals from the body. These signals are then processed by a computer to create detailed and sharp images, resembling sliced sections of the body. This allows doctors to examine abnormal areas in the body with precision, without posing any risks to the patient.

MRI has several advantages and indications:

1. MRI can accurately differentiate between different types of soft tissues, providing more accurate diagnoses, and can be used in all planes of the body, unlike computed tomography (CT) scans, which are mainly in the transverse plane.
2. It is particularly useful for non-bony parts of the body, such as the brain, spinal cord, and nerves (although CT scans are better for bones).
3. It is excellent for examining muscles, tendons, ligaments, and other soft tissues.
4. It can also visualize blood vessels without the need for contrast agents or radiation exposure, making it a safe and cost-effective option for current medical practice. Furthermore, it is more convenient for patients as it requires no preparation before or after the procedure, and patients can return home immediately after the scan.
5. Unlike CT scans, MRI does not expose the body to harmful radiation.

Systems or organs that can be observed via MRI:

1. MRI of the Nervous System is effective in examining the brain, spinal cord, and nerves throughout the body, allowing clear visualization of various diseases, such as early-stage ischemic stroke and abnormalities in the brainstem (which can be better detected than with computed tomography). It can also detect brain tumors and epilepsy.

2. MRI of the Musculoskeletal System is effective in examining the bones, spine, muscular and joint systems, aiding in the diagnosis of various diseases such as nerve impingement or ligament injury in various joints. Currently, MRI using electromagnetic waves (Magnetic Resonance Imaging, MRI) is widely used to aid in the diagnosis of bone and joint diseases. MRI can clearly visualize abnormalities within bones and accurately determine the extent of the disease, for better treatment planning. It is the fastest way to diagnose certain bone diseases, such as ischemia at the head of the femur. MRI can detect abnormalities even when regular X-rays appear normal. The most commonly examined joints are the knee and then the shoulder when suspected of having torn ligaments or soft tissue injuries within the joint. While regular X-rays may only show shadows of water in the joint, MRI can clearly visualize the various components within the joint and accurately determine any injuries.

3. Magnetic Resonance Angiography (MRA) can effectively examine the blood vessels of various organs such as abnormalities in brain blood vessels or hypertension in kidney blood vessels without the need for injecting a contrast agent. This method is safe and convenient, requires no preparation before or after the examination, and allows the patient to return home immediately.

4. Magnetic Resonance Cholangiopancreatography (MRCP) can examine the abdomen, bile ducts, and gallbladder, providing clear and suitable images for detecting diseases such as tumors, inflammation, or blockages in the ducts, as well as identifying lesions in the abdominal cavity.

Before undergoing an MRI (Magnetic Resonance Imaging), patients should be aware of certain warnings to ensure their safety and avoid any adverse effects. The following is a list of warnings that patients should keep in mind before getting an MRI:

1. Metal Implants: Patients with metal implants, such as pacemakers, cochlear implants, some cardiac stent, braces, and aneurysm clips, must inform their doctor or MRI technician beforehand. Metal can interfere with the MRI machine's magnetic field, leading to serious injury or malfunction of the implant.

2. Pregnancy: Pregnant women should avoid undergoing MRI scans during the first trimester unless it is medically necessary. Although MRI scans are generally considered safe during pregnancy, there is still a risk of potential harm to the fetus.

3. Claustrophobia: MRI machines require patients to lie down in a confined space for an extended period. Patients who suffer from claustrophobia may find the experience uncomfortable and should inform their doctor or MRI technician beforehand.

4. Tattoos: Patients with tattoos should inform their doctor or MRI technician beforehand as some tattoo inks may contain metal that can react with the MRI machine's magnetic field, leading to skin irritation or burns.

5. Gadolinium Contrast: Some MRI scans require the use of a gadolinium-based contrast agent. Patients with kidney problems may be at risk of developing nephrogenic systemic fibrosis, a rare but serious condition that causes skin thickening and damage to internal organs.

6. Anesthesia: In some cases, patients may require anesthesia to undergo an MRI scan. Patients should inform their doctor of any previous adverse reactions to anesthesia and should avoid eating or drinking for several hours before the procedure.

The MRI examination room is constantly filled with a high-powered magnetic field that affects the functioning of metal-sensitive tools. For example, it can stimulate the heart to beat rhythmically, attract all kinds of metal objects that are led by the magnetic field, delete data from magnetic tapes and cards such as ATM cards, credit cards, watches, thumb drives, or pocket PCs that contain iron components.

Here are the steps for getting an MRI:

1. After changing into appropriate clothing for the examination, the patient is escorted into the examination room.
2. The patient lies down on the examination table and a magnetic signal detector is placed on the body. The detector weighs about 1 kilogram.
3. The patient lies still and follows instructions, such as breathing in and holding their breath or refraining from swallowing saliva.
4. The body is moved to the center of the magnetic field for imaging, which may cause slight vibrations and movements.