FREQUENTLY ASKED QUESTIONS ABOUT an MRI
The length of the exam itself depends on the type of study being performed. MRI exams take an average of 20 to 45 minutes. There are a few variables that will determine time, including the part of your body we are scanning and whether your scan requires a contrast dye.
Physicians use the MRI scanner to examine one part of the body at a time. The scanner can take pictures of the head, neck, back, abdomen, pelvis, shoulder, elbow, knee, ankle, foot, blood vessels, and more.
Some patients feel claustrophobic in standard MRI scanners. Our wide-bore MRI is designed to accommodate larger patients and to minimize claustrophobia for people of all sizes.
The MRI scanner is wide open on both ends, well lit and ventilated.
The scanner works with strong magnetic fields. Inside an MRI machine there are parts called gradients. During a scan the gradients turn on and off so fast that they create a sound.
The area of the body being scanned will be in the center of the scanner. For many procedures — with the exception of scans of the head, neck, chest and upper abdomen — your head will remain outside the scanner.
If your healthcare provider prescribes an oral sedative for your exam we advise that you do have a driver.
An MRI is very safe. There are no health risks associated with the magnetic field or the radio waves used by the machine, nor have any side effects been reported. Patients with a pacemaker, certain types of aneurysm clips or certain other implants should not have an MRI. (See below for more about metal implants and scans.)
There is no radiation exposure associated with an MRI.
While an MRI scan has no known side effects, it is not recommended for pregnant women unless your healthcare provider believes it’s much more important to get an MRI.
You’ll need to remove all external metal objects—jewelry, clothing, etc.— for safety reasons related to the machine’s magnetic fields and because they appear on the MRI image.
As a general rule, no. However, please be sure to inform your technologist of any prior surgeries before your exam. Patients with the following should NOT have an MRI:
- Certain aneurysm clips
- Certain neurostimulators
- Certain implants that are not MRI-safe
- Tissue expanders
All implants that are placed by a surgeon have a manufacturer name and model number. Some surgeons give their patients cards with the manufacturer name and model number. The facility where the implant was placed should have record of what was implanted.
During the injection of a contrast dye, you may feel some slight pressure or discomfort as the joint is distended. The sensation is temporary and will pass within four to six hours after the procedure. Some soreness may also be present at the injection site for up to 24 hours.
You may resume regular activities immediately after the procedure. The radiologist will recommend, however, that you limit strenuous or “stress-bearing” activities on the affected joint for 24 hours following the procedure.
An MRI does not use X-ray radiation and a CT does. Instead, it creates high-quality images through the combination of a strong magnetic field and radio waves. It can detect certain diseases much earlier than other medical imaging techniques can, making it the diagnostic tool of choice for many physicians and many cases.