What is an MRI?
The MRI machine is a tube (or bore) surrounded by a large circular magnetic field, which a moveable bed moves through.
How does MRI work?
The MRI uses radio waves, a magnetic field, and a computer to produce images of body structures. Normal and abnormal tissues produce different images.
How long does an MRI last?
On average, an MRI lasts about 30 minutes.
What should I wear to an MRI?
Wear comfortable clothing with no metal, such as a sweatshirt and sweat pants.
Does an MRI hurt?
No, an MRI does not hurt.
I heard you have to lie still for an MRI? What if I have to sneeze or cough?
Sometimes a sneeze or a cough is uncontrollable, so we would just stop the scan and restart it once your sneeze or cough has passed.
What are the noises heard during an MRI?
With MRI, the patient stays in one position while the machine captures images from different directions using three small magnets inside the larger magnet. The banging noises are the small magnets altering the magnetic field to focus on a specific body part.
Do I have to drink anything or get an injection before an MRI?
Sometimes MRIs require a contrast injection placed through an IV in your arm. MRI systems do not use ionizing radiation, and the contrast material enhances the MRI images and has a very low incidence of side effects.
When is an MRI ordered?
MRI is an incredible diagnostic tool. The only better way to see inside your body would be through surgical intervention. Some of the instances in which is MRI is used include:
I had a CT for a possible bowel abscess. Why not an MRI? What is the difference between the two tests?
CT scans use radiation and MRI does not. CT is faster than an MRI, so in situations where an immediate diagnosis is necessary, CT is best. Your bowel has uncontrollable movement called Peristalsis, which causes a motion artifact on MRI, but a CT scan is a much faster exam and gives the doctor more information without motion.
What is the difference between MRI and an x-ray?
MRIs are multidimensional and x-ray is one-dimensional. X-ray images boney tissue but MRI can image soft tissue.
Why do I have to answer so many questions before an MRI?
Very careful screening is done with all patients prior to an MRI exam. The MRI uses a strong magnet so any ferrous (iron) metal is drawn to it. Therefore, thorough screening must be done on anyone entering the MRI scan room in order to determine whether the person has any metal in their body.
What metal is found in a person’s body?
Some metal is intentionally placed in a person’s body such as: pacemakers, aneurysm clips in the brain, dental implants. Some metal gets into the body by mistake, i.e., sheet metal workers may have metallic fragments in the eye. Either way, metal may make a person ineligible for an MRI and then alternative testing may be done.
Why do I have to have an x-ray of the head before an MRI?
If screening questions determine you may be at risk, an x-ray is done to look for metal fragments.
I have a total hip/knee replacement; can I safely get an MRI?
Orthopedic implants are usually not affected by an MRI even if they are ferromagnetic (iron) because they are imbedded in the bone. (Many orthopedic implants are now made of titanium, which is nonmagnetic.)
I have a marker in my breast. Would that interfere with an MRI?
Breast markers are okay to scan after 6 weeks.
If screening/testing determines that a person is at risk for injury during an MRI, what is done?
Other forms of imaging may be used if it is determined that an MRI may cause injury to the patient.
Is an open MRI as good as a closed MRI?
To date, no, an open MRI does not produce the same quality images as a closed MRI. Although imaging with an open MRI has improved over the years, a closed MRI continues to provide superior images.
I can’t stand being in small spaces, and I am afraid to get an MRI.
Claustrophobic patients and patients who are overweight have had a very hard time with the MRI procedure in the past due to the small opening and long length of the tube (called a bore). MRI machine manufacturers have been working to improve the machines to make them more patient friendly while still capturing quality images for physician use.
By June 2007, ACMH Hospital will have installed a new MRI machine, with a bore that is larger in diameter and shorter in length. It will allow about 60% of all MRI procedures to be done with the patient’s head and feet outside of the bore.
Currently, there are multiple techniques used by the ACMH physicians and staff to make your MRI test as comfortable and non-threatening as possible.
I’m overweight. Will I be able to get an MRI?
The new machine will accommodate weights up to 550 pounds.
How quickly are the results of testing available?
Your MRI results are available as soon as the testing is completed. They are interpreted by a Radiologist and sent to the ordering physician.
Will my insurance pay for an MRI?
You will have to check with your insurance carrier to make sure. Coverage varies with each plan, even with the same insurer.
What is the future of MRI?
Very small scanners are being developed that would image a specific part of the body such as an arm or a foot. The ability to visualize arterial and venous systems continues to improve; brain mapping (scanning the brain while performing a physical task such as squeezing a ball or looking at a picture) to understand how the brain works is developing; imaging strokes in their earliest stages is also being developed.