If you have ever had an MRI scan, you know that when you enter the room, it is oddly cold. This is because the two powerful magnets that form the core of the MRI machine need to be kept cool in order to function. The magnets are constantly working to maintain a strong and stable magnetic field.
There is a sensor inside the magnet's bore to monitor temperature. The GE “Working Safely” manual recommends that the room temperature be no greater than 700 F (210 C) during scanning (GE Medical Systems MR 3.0T Signa ExciteTM Learning and Reference Guide, 2003, p. 2-22).
The MRI room will likely be cold; this ensures a proper working environment for the machine's magnets.
Because of MRI radio waves, some people report feeling a little warm during the procedure. Your temperature may go up by a degree, but don't worry — it's not dangerous.
In addition, the MRI environment requires a cool ambient temperature for proper magnet function, which further predisposes infants and children to heat loss, so they may be at risk of hypothermia. Conversely, the MRI scanner generates radiofrequency radiation (RFR), which is absorbed by the patient.
The AC system in CT room will cause noise which is another issue for the patient comfort and it makes the communicating with the patient very hard if the patient can't hear well due to the fan noise. The point of cooling the CT scanner is to protect the machine and maximize its lifespan.
The MRI machine uses a combination of a strong magnet, radio transmitter and receiver. When the sequences are performed, electric current is sent through a coiled wire-an electromagnet. The switching of the currents causes the coils to expand making loud clicking sounds.
If you need to cough or get an itch, tell them and they can get you out, or give you a short break between sequences. Then you are moved out of the machine, released, have your plastic tube removed and can go home.
What medications are used? Propofol will be given through an I.V. to induce sleep. This medication has a short duration of action and a rapid recovery time and is administered to make sure you remain asleep during the entire MRI study.
Swallowing can lead to head motion artifacts. If you can avoid swallowing during a scan, the data quality will be better. If trying not to swallow makes you gag or swallow suddenly, then it's best to just swallow normally.
Since the MRI machines are magnets, it is best to not apply deodorants, antiperspirants, perfumes, or body lotions before the examination. These items contain metals that might interfere with the magnetic field inside the MRI machine and cause you to have distorted images and wrong results.
Because an MRI machine requires so much energy, it saves on overall power usage by leaving the magnet running all the time, rather than constantly turning it on and off everyday. Therefore the magnet is always on! The electricity flows through miles and miles of tightly wound wires (or coils) inside the MRI machine.
You must lie very still during the scan. If you move, the MRI scan pictures may not be clear.
Yes! Though we strive to make your MRI scan as comfortable as possible, the scan itself can still be stressful for some patients. We recommend that you bring a close friend or family member into the scanning room with you. They will be able to sit by your side during your Open MRI scan.
Various clothing items such as athletic wear (e.g., yoga pants, shirts, etc.), socks, braces, and others may contain metallic threads or metal-based anti-bacterial compounds that may pose a hazard. These items can heat up and burn the patient during an MRI.
To avoid the images being blurred, it's very important to keep your whole body still throughout the scan until the radiographer tells you to relax. A single scan may take from a few seconds to 3 or 4 minutes. You may be asked to hold your breath during short scans.
Keep your eyes closed or even wear a blindfold.
It's much easier in an open MRI it's wider than a standard scanner, so patients shouldn't feel any walls touching them.
If You Have an Overactive Bladder
This feeling of urgency can make it harder to hold urine in. While you may still experience this urgency to a degree, not drinking for several hours before your procedure can make you less likely to experience incontinence during the scan.
It's important that patients remove all clothing prior to their MRI exam. We ask patients to remove: All outer clothing, including shoes. Bras or any undergarment that could have metal in it.
There also aren't any restrictions on what you can do after the test. “Patients can resume their normal activities immediately after the MRI scan,” Dr. Taouli says. (Unless you had any drugs for sedation or anxiety, in which case you may need someone to drive you home; be sure to ask your doctor about this beforehand.)
There aren't any side-effects from the MRI scan itself. However, if you've had an injection of contrast medium (dye) as part of the investigation, you may have some side-effects which might include a skin rash, dizziness, a headache, and nausea.
Adverse Events
Second degree burns are the most commonly reported patient problem. Other reported problems include injuries from projectile events (objects being drawn toward the MRI scanner), crushed and pinched fingers from the patient table, patient falls, and hearing loss or a ringing in the ear (tinnitus).
A brain MRI can take about 30 minutes to an hour to complete. It may take longer if you're getting a brain MRI with contrast. Your healthcare provider will be able to give you a more exact time range based on the specific reason for your scan.
MRIs take a long time to complete because they take many hundreds of images of your tissue in slices. They then build this up into a three-dimensional representation that doctors can study.