Importance of the MRI Machine
An MRI (Magnetic Resonance Imaging) machine is used by doctors to verify or diagnose
problems in people’s soft tissue or bones. This technique uses magnetic fields and radio waves
to map out soft tissues and bone in the body. This technique is extremely important in
diagnosing knee, brain, and shoulder injuries.
The Machine
An MRI machine is usually quite large, though newer styles are smaller and more efficient. MRI
machines are large, tubular magnets. They do not have any
writing on them. They are extremely plain. They are
usually in a small, cold, plain room to minimize any
interference with tests. A patient lays down on the bottom
opening of the platform of the MRI and is slid into the
machine by an operator. Once the person is in the machine
it is turned on. The machine creates a magnetic field
through the body that lines up all the hydrogen atoms within
the subject’s body. Once the magnetic field is created, the
machine sends radio waves through the body to excite the
hydrogen which then give very small signals. These small
signals are used to make the cross-section MRI pictures that the doctors will analyze. The
Machine can do 3-D imaging, so soft tissue sites of particular interest within the body can be
looked at in great detail from several angles.
MRI Pictures
The MRI is used predominately to test the brain and spinal cord. It is able to help doctors
diagnose aneurysms, disorders in the eye and internal ear, Multiple
sclerosis, Spinal cord injuries, strokes, and tumors –benign and
cancerous. Doctor can use a functional MRI (fMRI) to get a more
detailed picture in the instance that the MRI doesn’t give enough
detail; this happens in the case of brain injuries. The MRI is able to
generate a picture of the heart and blood vessels to check for
abnormalities like: size/function of the heart’s chambers, thickness
and movement of heart walls, how much damage heart attacks and
disease caused/cause, any structural issues with major vessels and
arteries – aneurysms or cut, and any inflammation or blockages in the
vessels of the patient. The MRI can show inconsistencies of the body’s organs: liver, kidneys,
spleen, pancreas, uterus, ovaries, prostate, and testicles. These inconsistencies are then checked
for cancerous or benign tumors. It can be used to back up results from a mammography which
picks out breast cancer for women who have very dense tissue in their breasts. The MRI is also
crucial for orthopedic doctors (bone/sports doctors). The MRI helps them distinguish joint
problems like arthritis, joint injuries from trauma or overuse like meniscus or ACL tears in the
knee, disk abnormalities in the spine like slipped disks, bone infections, and tumors of bones or
soft issues like cartilage. The development of the MRI machine made it easier for doctors to
know when something is wrong with tissue instead of having to perform surgery as the only
means of knowing. The development of this machine minimized uncertainty that doctors had
about injuries or when and how to perform surgery.
Associated Risks
The MRI is not different from any other medical device in the fact that there are risks involved
with its use. People that have metal in their body are going to get improper readings – the metal
messes up the magnetic fields due to diffraction of charge. For this reason, subjects are asked to
take out metal jewelry, and other precautions may be taken. Some special cases that must be
mentioned prior to an MRI are joint prosthetics, artificial heart valves, pacemakers, metal
implants or fragments, cochlear implants, heart defibrillator. It is also important the technician
completing the MRI knows about the patient’s liver or kidney issues because these issues need to
be taken special interest in photographs.
Preparation for an MRI
The subject getting an MRI will be asked to keep to his or her daily routine. Before the MRI, the
subject will put on a gown. He or she will be asked to remove all metal: jewelry, hair
accessories, glasses, dentures, hearing aids and underwire bras. The subject will be able to return
to normal life after the MRI.
The Test
The subject lies on a movable board connected to the machine. The subject enters the MRI’s
open tube to begin the test which is controlled by a technician. A technician will be able to talk
to the subject via earphones that the subject wears. The subject is able to talk back unless
sedated – this is rare. The MRI creates a magnetic field around the subject and sends radio
waves through the subject – the subject will not feel any of this since it is microscopic. The
machine makes continuous tapping and other obnoxious noises, so the subject will have
earphones on. Sedatives can be given to subjects that struggle with claustrophobia. The patients
getting blood vessels analyzed will get an intravenous injection so that his or her vessels are
more easily seen in the processed images. The test takes around an hour. Any movements can
cause blurred images and increase the test time.
Results
The results of an MRI will be interpreted by a specialist – a radiologist- who is a doctor trained
in reading the information from specialized tests. The information that the radiologist finds are
then sent to the subject’s doctor. The doctor will discuss the conclusions of the test and let the
subject know what to do with the information.