Magnetic Resonance Imaging (MRI)
MRI Scan is a type of scan that is used by doctors to diagnose you or to check how you respond to treatment. In this, doctors use powerful magnets, radio waves, and a computer to scan detailed pictures of your body.
MRIs do not use the damaging ionizing radiation of X-rays, unlike X-rays and computed tomography(CT)scans.
Why would the MRI be needed to be done?
With the help of MRI, a doctor can diagnose the injury or disease and able to monitor the performance of the patient towards the treatment.
You can do MRIs on different parts of your body. It’s especially used to look soft tissues and the nervous system.
What MRI looks for in the heart and blood vessels?
- Blocked blood vessels
- Damage caused by a heart attack
- Heart disease
- Problems with the structure of the heart
What MRI looks for in the brain and spinal cord?
- Blood vessel damage
- Brain injury
- Multiple sclerosis
- Spinal cord injuries
What we found in the MRI of the bones and joints
- Bone infections
- Damage to joints
- Disc problems in the spine
- Neck or low back pain with nerve signs
What else can be check using MRI
- Breasts (women)
- Ovaries (women)
- Prostate (men)
To maps brain activity, a special kind of MRI is used which is called a functional MRI(fMRI). A doctor conducts this test to check the blood flow in your brain, and to check which area of your brain reacts when you perform certain tasks. It can be used to detect brain problems, like stroke effects, or if you need brain surgery for epilepsy or tumors, then it can be used to do brain mapping. This plays an important role in planning your treatment.
How to Prepare for an MRI?
Before your MRI Scan, let your doctor know if you:
- Have any health issues such as kidney and liver problems
- Had Surgery recently
- Have Asthma, or if you are allergic to food or medicine
- Might be pregnant or pregnant
You are not allowed to do an MRI scan while having any metals, and it is strictly prohibited in the MRI room as the magnetic field in the machine can attract metal. Before MRI, inform your doctor if you have any metal object or device that can be harmful to you or create problems during the test. It includes:
- Artificial heart valves
- Body piercings
- Cochlear implants
- Drug pumps
- Fillings and other dental work
- Implanted nerve stimulator
- Insulin pump
- Metal fragments, such as a bullet or shrapnel
- Metal joints or limbs
- Pacemaker or implantable cardioverter-defibrillator (ICD)
- Pins or screws
If you have any tattoos on your body, then you must consult with your doctor as some inks contain metal.
Wear loose, comfortable clothes that don’t have metal fasteners on the day you are having tests. You might be asked to wear a gown during the test.
You are not allowed to carry these things with you in the MRI room which includes:
- Cell phone
- Hearing aids
- Underwire bra
If you feel uncomfortable or nervous before MRI, then let your doctor know about this. You might get open MRI or get medicines to keep you calm before the MRI.
MRI machine looks like a large tube with a hole at both ends. It is surrounded by a magnet. You slide into the tube after you lie on a table.
The body part which needs to be scan is inside this tube, and the rest of the body is outside the machine.
If you have claustrophobia(a fear of tight spaces) or you are overweight, then open MRI is best for you. Although the image quality of open MRI is not at that level which you get in closed MRI.
What happens during the MRI Scan
Before some MRIs, you’ll get contrast dye into a vein in your hand, or arm which helps the doctor to scan body structures more clearly. Gadolinium is the dye that often uses in MRIs. It can leave the taste of metal in your mouth.
When you are in the scanner, the technician will communicate with you via intercom to confirm that you are comfortable, and if you are not comfortable then let him know, and you can request him to stop the scan.
During Scan, the MRI machine creates a magnetic field inside your body. A computer creates a series of pictures by taking signals from the MRI. The thin slice of your body is shown in each picture.
During the test, you might hear a loud thumping or tapping sound because the machine creating energy to take pictures inside your body.
For your comfort, headphones will be provided to you to muffle the sound. MRI stimulates nerves in your body, which creates a twitching sensation in you during the test.
You don’t need to worry about this, and this is normal. MRI scan is of 20-90 minutes.
How does an MRI scan work?
Most of the human body is made up of water molecules, which includes hydrogen and oxygen atoms.
Proton is a smaller particle that is at the center of each hydrogen atom, and they are like tiny magnets and very sensitive to magnetic fields.
When you line in the scanner, then the protons in your body line up in the same direction, and it helps the magnet to pull the needle of a compass.
Short bursts of radio waves are sent to certain areas of the body, knocking the protons out of alignment.
Protons realign after the radio waves turned off. This sends the radio signals to the receiver.
The information about the exact location of the protons can be traced in the body.
It also helps to distinguish the tissue in the body as the protons present in various types of tissue realign at different speeds and produce distinct signals.
The signals coming from the millions of protons in the body are combined to create a detailed image of the body.
Who can not do an MRI Scan?
Unless necessary, pregnant women should not get an MRI during the first trimester(the stage when baby’s organs develop) and shouldn’t get contrast dye.
If you have a kidney problem, shouldn’t get contrast dye.
Certain people who have metal inside their body can’t get this test, including those with:
- Some clips used to treat brain aneurysms
- Pacemakers and cardiac defibrillators
- Cochlear implants
- Certain metal coils placed in blood vessels
MRI Scan Report
Radiologist(a specially trained doctor) will examine the results of your MRI and send the report to your doctor.
Your doctor will go through the report and let you know what you need to do now.