Magnetic resonance imaging, or MRI, creates detailed images of tissues and organs without using x-rays. It does this using powerful magnetism combined with radio waves and rapidly changing magnetic fields that produce signals which computer programs interpret as pictures.
As the MR LINAC produces loud tapping or knocking noises, earplugs may be necessary. Your radiation therapist should provide them to you.
What is MRI?
MRI produces highly detailed black-and-white pictures of organs and structures within the body without using radiation (x-rays). It allows physicians to visualize bones, soft tissues, blood vessels and many other internal organs without exposure to radiation (x-rays). Furthermore, MRI may be used to detect tumors or abnormalities as well as assess injuries or disease; either alone or with other diagnostic tests.
An MRI exam involves lying on a table that slides into a large cylindrical scanner, where a very powerful magnetic field creates an inert yet magnetically charged field that causes hydrogen atoms in your body to change their natural alignment, producing radio waves which are then used by computers to create images. A contrast material can also be injected through veins during an MRI scan to help physicians see certain areas more clearly, while magnetic resonance spectroscopy allows doctors to examine chemical components of tissues or organs like livers more thoroughly.
For optimal images, it is critical that you remain completely still during the MRI procedure. A technologist will monitor you from an adjacent room and may give medication to help relax during this procedure if necessary. Because an MRI machine produces loud thumping and humming noises, ear plugs or headphones will be provided to dampen them down – plus an intercom is installed so you can reach the technician anytime!
Before entering an MRI scanner room, you will be required to remove jewelry, eyeglasses or hearing aids, hairpins and any other personal belongings from your person. A locker will be provided so these can be safely stored along with other personal effects. There may also be guidelines pertaining to eating and drinking prior to an MRI exam depending on where it takes place; please check with your provider.
Certain metal implants and medical devices in your body, including pacemakers and aneurysm clips, may interfere with the magnetic fields created by an MRI scanner and should be reported. Also be sure to notify your health care team if you think you may be pregnant, since exposure can affect fetuses as well.
How does MRI work?
MRI uses radio waves and magnetic fields to produce images of body tissues, which a radiologist can then use to pinpoint problems in the area under inspection. The procedure does not use radiation and is painless – patients simply lie on a table that slides into a donut-shaped scanner shaped like a large cylindrical cylinder with their feet resting comfortably, as their radiographer ensures body movements don’t blur pictures created during scanning; some patients may be given sedatives prior to their exam to help keep still during scanning sessions.
Before an MRI begins, patients are asked to remove any metal objects like wristwatches and keys as well as wear a cotton gown during the test. Although most MRI machines are quite quiet during their operation, technologist will ask you to communicate using an intercom inside the scanner; some MRI machines also feature open space layouts which may provide added relief from feeling enclosed during your exam.
As soon as an MR scanner turns on, an extremely strong magnetic field is created which aligns atomic particles called protons that exist in water molecules–which make up around 70% of human bodies–with protons created by its powerful magnetic field. Each hydrogen atom contains one positive proton at its nucleus which acts like a microscopic magnet sensitive to this powerful magnetic field created by the scanner. Radiologists may start an MRI by periodically pulse pulsing this magnetic field on and off so protons spin out of alignment with said magnetic field while receiving receivers pick them up from these signals that then processed into clear black-and-white images depicting areas being scanned by computers before being sent on to produce clear black-and-white images of any areas being scanned by computerized images created from these signals received.
Radiologists often apply small amounts of contrast agent to highlight certain tissues or structures; this is especially helpful for patients suffering from infections or diseases affecting blood vessels and organs. Once images have been reviewed by radiologists, reports are sent back to physicians; in some MRI centers patients can even access their scans directly via website or patient portal.
What are the benefits of MRI?
MRI scans produce more detailed pictures than other medical imaging techniques like CT and ultrasound, helping physicians diagnose diseases and determine the optimal course of treatment for you. Since MRI does not contain radiation, the images created with it are safe for pregnant women and children; additionally, its images can detect more subtle changes to soft tissues than other techniques; it’s especially good at spotting tumors, abnormalities in blood vessels, brain or other body issues that require attention.
At an exam, you will lie on a moveable table that slides into a tunnel-like machine. Although the test itself is noninvasive and pain-free, some patients may find staying still for the entire exam difficult or feel claustrophobic inside. Your physician will discuss all available solutions to ensure maximum comfort and safety during your experience.
An MRI technician will assist in positioning you on the exam table. They may use straps or bolsters to help keep you still, while in certain instances contrast dye may be injected directly into a vein to improve images. If allergic to contrast dye, be sure to inform your physician immediately if symptoms such as itching, swelling or rashes arise after your appointment.
An MRI scanner’s powerful magnetic field can have an adverse impact on metal objects such as watches or earrings, so anyone wearing such items will receive goggles to wear during their test. Furthermore, any clothing with metallic threads or zippers should also be removed prior to going in for examination. Afterward, the results of your exam will be reviewed by a radiologist who will send them along to their physician to be discussed with them later.
MRI is one of the most accurate ways of detecting certain kinds of tumors. Additionally, it can also be used to examine other kinds of tissue like herniated disks in spine or ruptured aneurysms in brain. Surgeons use MRI as part of surgery for brain tumor removal or treating burst blood vessels (aneurysm) or arteriovenous malformation (AVM). Furthermore, it has many applications in liver, pancreas, and bile duct conditions evaluation.
What are the drawbacks of MRI?
The magnetic field of an MRI scanner can be very strong. It may attract metal objects (such as paper clips and hair pins) brought into the scan room, making them projectiles which could harm patients or others in the room. Therefore, patients are advised to wear hospital gowns and request healthcare providers remove any metallic objects brought into the room from ferromagnetically charged surfaces like paper clips and hair pins that they bring with them into the scan room. In order to stay safe during an MRI session, such people are strongly encouraged to wear hospital gowns while healthcare providers remove any metallic objects brought into the scan room before entering. Furthermore, MR environments present specific safety risks for people implanted devices like artificial joints/stented devices/accessories such as oxygen tanks/external insulin pumps- patients should consult with their doctors in advance about possible risks during an MR session.
The magnetic field of an MRI scanner can distort certain cardiac devices with magnetic coatings, potentially rendering them inoperable and leading to irregular heartbeats or rhythm disturbances that require replacing or repairing of devices.
Although MRI does not use radiation, its magnetic field can produce small amounts of heat which may impact soft tissues in the body. Therefore, it is vital to remain still during an exam because movement can distort images and require another scan; some patients find it hard to remain still due to nervousness or claustrophobia; should this occur, sedatives may be prescribed in such instances.
Since MRI utilizes powerful magnets, pregnant women should not undergo this test during their first trimester of gestation. Women should instead discuss their individual medical situation with a radiologist to help decide whether the benefits outweigh risks associated with having an MRI performed.
