Magnetic Resonance Imaging, or MRI, technology uses a large magnet and radio waves to capture detailed images of soft tissues and organs.
MRI scans are useful for examining the brain, neck and spinal cord. Our physicians also use them to distinguish healthy tissue from diseased or injured tissue for conditions from torn ligaments to tumors.
MRI is one of the fasted growing areas of medical imaging. MRI is capable of producing images in an infinite number of image planes through the body. To produce this image, MRI uses a large magnet that surrounds the patient in addition to radio frequencies and a computer.
As the patient enters an MRI scanner, his or her body is surrounded by a magnetic field up to 8,000 times stronger than that of the earth. The machine uses this magnet field to detect the radio frequencies emitted by the millions of atoms that make up our bodies.
This data is then computer-processed to produce very detailed images of the human anatomy. Physicians get the absolute clearest picture of complex body parts like the brain and the tiny nerves that make up the spinal cord.
Because MRI uses no ionizing radiation and presents no apparent risk to patients, it is replacing more painful and risky examinations such as spinal injections.
MRI is a safe procedure for most patients, although it generally is not recommended for pregnant women. If you are pregnant, let your physician know.
Also, because the body is exposed to a strong magnetic field, patients who have a pacemaker, cochlear implants, or aneurysm clip should check with a physician before undergoing an MRI examination.
Patients who have other types of metal implants and patients who have been exposed to shrapnel or whose eyes have been exposed to metal shavings also might not be candidates for MRI; it's important to let your physician know if these conditions apply to you.
For similar reasons, women undergoing an MRI exam should not wear eye shadow, because it sometimes contains metallic substances.
If you are claustrophobic or experience pain when lying on your back for more than 30 minutes, let your doctor know. He or she may be able to prescribe a relaxant or pain medication.
Before your examination, an MR technologist will explain the procedure to you and answer any questions you might have. The MR technologist will ask you several questions about your medical history. Some patients may be required to have lab work before the procedure.
It is helpful to have a list of current medications and dosages you are taking.
An MR technologist, also known as a radiologic technologist, is a skilled medical professional who has received specialized education in the areas of anatomy, patient positioning, patient care, imaging techniques and MR procedures.
During the Examination
Examination time depends upon the part of the body being examined but typically ranges from 30 minutes to an hour.
You will be asked to undress, remove all jewelry, and put on a hospital gown. Remember, the magnet will damage wristwatches and erase credit cards and bank cards, so don't take them into the exam room with you. You will be provided with a secure place to store these items during your examination.
For most types of exams, the MR technologist will wrap a special coil around the body part that is being examined. This coil helps concentrate the radiofrequency pulses.
The MR technologist then will position you on a padded, movable table that will slide into the opening of the scanner.
You may be given a contrast agent to highlight internal organs and structures. The contrast changes the relaxation rate of protons in the body, illuminating organs and tissues and making tumors, vessels and scar tissue appear brighter.
You won't feel anything during the scan, but you may hear intermittent humming, thumping, clicking, and knocking sounds. These are the sounds of the magnetic gradients turning on and off. Some MR centers provide patients with headphones or earplugs to help mask the noise.
The MR technologist will not be in the room during the scan but will be able to observe you through a window from a room next door and will be able to hear you and talk to you through a two-way microphone system.
The technologist will tell you when each scan sequence is beginning and how long it will last. You will be asked to remain as still as possible throughout the sequence.
When the exam is complete, your MR scans obtained will be given to a radiologist who specializes in the diagnostic interpretation of medical images.
Magnetic Resonance Safety
Unlike x-ray exams, which use radiation, magnetic resonance (MR) images are created with magnetic fields and radio waves. MR scanning is a very safe and effective technique for examining the body's soft tissues, such as organs, muscles, ligaments and tendons.
However, because MR scanning uses a powerful magnet, patients need to know about some special precautions and check-in procedures.
No metal is allowed in the room where MR scans are performed because metal objects are attracted to the magnet. The magnet is always on, whether or not scanning is going on. On rare occasions, patients and health care professionals have been injured when an object suddenly was drawn to the magnet. Also, metal objects can create artifacts on MR scans, making it difficult or impossible to see the patient's anatomy.
For your own safety and comfort, for the safety of the staff that will care for you, and to ensure a high-quality diagnostic exam, please follow these guidelines:
- You will not be allowed to wear a watch or any jewelry, including a body piercing, during the exam. It may be best to leave these items at home, although some facilities provide a safe place to store your valuables during your exam.
- Barrettes, hairpins, eyeglasses, dentures, and hearing aids also must be removed. Some types of cosmetics contain small amounts of metal, so avoid wearing any makeup on the day of your exam.
- Also avoid clothing with metal zippers, rivets, buttons, or metallic fabric. Empty your pockets of all metal items, including coins, money clips, credit cards, pens, pocket knives, keys, safety pins, and paper clips.
- Permanent metal dental work, such as crowns, fillings, and non-removable braces, do not normally cause a problem during MR scans.
- Metal wheelchairs and oxygen tanks are not permitted near the MR magnet. However, special MR-safe versions may be available at the facility where your exam will be performed.
- Tell the technologist if you ever have suffered a gunshot wound or any type of accident that may have left metallic particles in your body. Depending on the type of metal and where it is located, you may not be able to have an MR exam.
- If you have questions about any medical equipment you use, ask the MR technologist who will perform your exam. He or she is a skilled professional educated in anatomy, positioning, and the safe use of magnetic resonance technology.
The technologist will screen you before your exam and will check you for metal objects and ask you a series of questions about metal that might be in or on your body. Think carefully about these questions, answer them truthfully and ask the technologist if there is anything you don't understand. Be sure to tell the technologist if you have any of the following:
- A pacemaker or artificial valve in your heart.
- Metal pins, plates, rods, screws or nails anywhere in your body.
- Wire sutures or surgical staples.
- An intrauterine device (IUD) or diaphragm.
- An insulin pump.
- An aneurysm clip.
- A joint replacement.
- An ear implant.
- A stent, filter or coil in any blood vessel.
- Any type of prosthesis, including a penile implant or artificial eye.
- Permanent (tattooed) makeup, such as eyeliner or lip coloring.
By knowing these important precautions and cooperating fully with the MR technologist, patients can help ensure that they have a safe and useful exam.
MRI (Magnetic Resonance Imaging) technology uses a large magnet and radio waves to capture detailed images of soft tissues and organs. MRI scans are useful for examining the brain and spinal cord. Our physicians also use them to distinguish healthy tissue from diseased or injured tissue for conditions from torn ligaments to tumors.
MAGNETOM™ Avanto MRI with 1.5 Tesla magnet - This MRI provides a quieter, quicker, and more comfortable MRI experience for patients.
It offers 97 percent acoustic noise reduction without compromising image quality and also provides fast image acquisition with parallel imaging in all dimensions, including head-to-toe, front-to-back and side-to-side. Patients can now experience the shortest exam times available for MRI scans.
The Magnetom Avanto MRI provides whole-body coverage with a comfortable and inviting design. The Body Matrix coil weighs only 33.5 ounces, making it significantly more comfortable, especially for very sick cardiac or oncology patients.
And with the whole-body coverage capability, there is no patient or coil re-positioning for most exams. With the Avanto, MRI physicians receive detailed images, not available with a completely open MRI, of the tiniest areas which are necessary to examine neurological structures.
Magnetom™ Skyra 3T MRI - When it comes to MRIs, a stronger magnet means clearer images and the 3T is the most powerful magnet in clinical use today. Our Magnetom® 3T Skyra MRI delivers the crystal-clear images (not possible with a completely open MRI) that physicians need with the comfort and speed every patient wants.
Siemens Magnetom Symphony MRI with 1.5 Tesla magnet - This powerful MRI provides the same quality of images as our hospital-based MRI systems, and is almost as quick, providing total body scans in less than 20 minutes. It can accommodate differently-abled patients with a special lift, wheelchair, and gurney capabilities.
The MAGNETOM™ Espree - This MRI accommodates patients of all sizes, including the obese, elderly and children, providing more headroom and comfort for patients who tend to become claustrophobic.
Almost 60 percent of exams can be performed with the patient’s head outside of the system due to the shorter length of the magnet. The high-power Espree, like the Avanto and Symphony MRI units, delivers crystal clear 1.5 Tesla magnet images not available with a completely open MRI.
FONAR’s The Stand-Up MRI - FONAR's The Stand-Up MRI™ allows full weight bearing, standing, and sitting imaging of the spine, as well as imaging in the "position of pain." Often this upright position is the only position in which the patient's symptoms occur.
Coupled with the MRI's unparalleled ability to "see" soft tissues, this machine gives physicians a more global view of pathology and its impact on function.
The Stand-Up MRI™ is also the only whole-body MRI with the ability to perform Positional Imaging™. Patients can be scanned in a multitude of positions including standing, sitting, flexion, extension, rotation, lateral, and recumbent. Unusual patient positions that are difficult or impossible on conventional "lie down" scanners are routine on FONAR's The Stand-Up MRI™.
In addition, the Stand-Up MRI™, is a non-closed architecture imaging system, making it the most non-claustrophobic, whole-body MRI scanner. Patients can walk into the magnet, complete their scans and walk out.
The magnet's front-open, the top-open design provides patients with an unprecedented degree of comfort. To make the procedure even more comfortable, they can even watch a TV monitor mounted on the scanner room wall.
Vitrea 3-D Imaging Workstation - Vitrea software is an advanced visualization solution that creates 2D, 3D, and 4D images of human anatomy from CT (computed tomography) and MR (magnetic resonance). With this tool, physicians can easily navigate within these images to better understand disease conditions.