What Is MRI | How MRI Works | The Uses And Side Effects
Recently Updated On: January 10th, 2018
What Is MRI?
“What is MRI”? the question is mooted whenever a doctors recommended you for this test. MRI or the Magnetic resonance imaging (MRI), also known as nuclear magnetic resonance imaging, is a scanning technique for creating detailed images of the human body.
The scan uses a strong magnetic field and radio waves to generate images of parts of the body that can’t be seen as well with X-rays, CT scans or ultrasound. For example, it can help doctors to see inside joints, cartilage, ligaments, muscles, and tendons, which make it helpful for detecting various sports injuries.
MRI is also used to examine internal body structures and diagnose a variety of disorders, such as strokes, tumors, aneurysms, spinal cord injuries, multiple sclerosis, and eye or inner ear problems.
It is also widely used in research to measure brain structure and function, among other things.
How MRI Works?
What Is MRI Magnetic Strength:
The human body is mostly water. Water molecules (H2O) contain hydrogen nuclei (protons), which become aligned in a magnetic field. An MRI scanner applies a very strong magnetic field (about 0.2 to 3 teslas, or roughly a thousand times the strength of a typical fridge magnet), which aligns the proton “spins.”
The scanner also produces a radio frequency current that creates a varying magnetic field. The protons absorb the energy from the magnetic field and flip their spins.
When the field is turned off, the protons gradually return to their normal spin, a process called precession. The return process produces a radio signal that can be measured by receivers in the scanner and made into an image.
What is Mri Used for?
An MRI is used for an extremely accurate method of disease detection throughout the body. It is most often used after the other testing fails to provide sufficient information to confirm a patient’s diagnosis.
Mri used for checking the bleeding or swelling in the brain while in trauma or in case of head injury. Other abnormalities often found include brain aneurysms (bulging, weak area in the wall of an artery that supplies blood to the brain), stroke, tumors of the brain, as well as tumors or inflammation of the spine.
Neurosurgeons use an MRI scan not only in defining brain anatomy but in evaluating the integrity of the spinal cord after trauma. It is also used when considering problems associated with the vertebrae or intervertebral discs of the spine.
An MRI scan can evaluate the structure of the heart and aorta (largest artery of the body), where it can detect aneurysms or tears. MRI scans are not used for the first line of imaging test for these issues or in cases of trauma.
It provides valuable information on glands and organs within the abdomen, and accurate information about the structure of the joints, soft tissues, and bones of the body. Often, surgery can be deferred or more accurately directed after knowing the results
How To Read MRI Report?
An MRI machine uses a magnetic field to produce clear, detailed images of the brain, spine, heart, bones, and other tissues, making it an extremely valuable tool for doctors. Most modern MRI centers can give you a copy of your MRI on a disc or flash drive after your appointment — you may not even need to ask for it specially.
While it takes a doctor to make a diagnosis from an MRI, viewing and analyzing your MRI at home is easy — just don’t jump to any conclusions without consulting with a doctor. See How to read MRI report step by step:
What is MRI safety profile?
Mri Side Effects:
MRI during Pregnancy:
Unlike other imaging forms like X-rays or CT scans, MRI doesn’t use ionizing radiation. MRI is increasingly being used to image fetus during pregnancy, and no adverse MRI side effects on the fetus have been demonstrated.
Still, the procedure can have risks, and medical societies don’t recommend using MRI as the first stage of diagnosis.
Because MRI uses strong magnets, any kind of metal implant, such as a pacemaker, artificial joints, artificial heart valves, cochlear (an electronic device for the ear) implants or metal plates, screws or rods, pose a hazard. The implant can move or heat up in the magnetic field.
Several patients with pacemakers who underwent MRI scans have died, patients should always be asked about any implants before getting scanned. Many implants today are “MR-safe,” however, sources said.
The constant flipping of magnetic fields can produce loud clicking or beeping noises, so ear protection is necessary during the scan.
What is MRI test result?
After the MRI scanning is completed, the computer generates visual images of the area of the body that was scanned. These images can be transferred to film (hard copy).
A radiologist is a physician who is specially trained to interpret images of the body. The interpretation is transmitted in the form of a report to the practitioner who requested the MRI scan. The practitioner can then discuss the results with the patient and/or family.
Scientists are developing newer MRI scanners that are smaller, portable devices. These new scanners apparently can be most useful in detecting infections and tumors of the soft tissues of the hands, feet, elbows, and knees.
The application of these scanners to medical practice is now being tested.
MRI Vs CT Scan
Many patients ask about the differences between a CT (Computed Tomography) scan and an MRI (Magnetic Resonance Imaging) scan: “Which is better?” or, “Should I have one over the other?” While the machines look similar, what occurs is quite different.
A CT scanner sends X-ray beams through the body as it moves through an arc taking many pictures. A CT scan sees different levels of density and tissues inside a solid organ, and can provide detailed information about the body, including the head (brain and its vessels, eyes, inner ear, and sinuses), chest (heart and lungs), skeletal system (neck, shoulders and spine), pelvis and hips, reproductive systems, bladder and gastrointestinal tract.
Advances in CT scanning include increased patient comfort, faster scanning times and higher resolution images. As scans become quicker, X-ray exposure has decreased, providing better images at lower doses.
The average CT scan today exposes patients to less radiation than what airline passengers receive on long flights. That said, anyone having a CT scan should talk to their doctor about the risks from radiation exposure versus the benefits of early diagnosis.
What is MRI working Procedure than ct?
Unlike CT scans, which use X-rays, MRI scans use powerful magnetic fields and radio frequency pulses to produce detailed pictures of organs, soft tissues, bone and other internal body structures.
Differences between normal and abnormal tissue are often clearer on an MRI image than a CT. And while there is no radiation involved in an MRI scan, it is safer than Ct scan.
It can be a noisy exam and takes longer than a CT. A specially trained radiologist only can interpret the scan and help to achieve a quick and accurate diagnosis. Hence while comparing between MRI Vs CT Scan, MRI results are always better.