Why did my doctor order an mri?
Whenever your doctor requires top-quality
anatomic portrayal, especially soft tissue, chances are that
an MRI will be the modality of choice. Unfortunately, the
decision to prescribe or not to prescribe an MRI will not
always be made on the basis of diagnostic quality.
Sometimes, in a well-meaning attempt
to save money for the patient or the insurance company, a
physician will choose a less-expensive procedure, hoping that
he or she will receive sufficient information to make a correct
diagnosis. If the less-expensive test proves inadequate, however,
and an MRI is prescribed later, the attempt to save money
will have been futile. Even worse, the condition may be inaccurately
diagnosed using a less definitive, non-MRI procedure.
A recent court case helps illustrate
the point. A Minnesota jury recently awarded a couple $1.25
million because two physicians treating their son, Philip,
at Park Nicollet Medical Center failed to prescribe an MRI
to assist them in making their diagnosis. Over a period of
18 months beginning in the fall of 1989, they treated the
boy for attention deficit hyperactivity (ADH). Finally, when
no progress was noted, the parents took it upon themselves
to consult a neurologist at the University of Minnesota. The
specialist promptly prescribed an MRI and soon afterward properly
diagnosed the boy's condition as metachromatic leukodystrophy,
a degenerative brain disease which can often be reversed with
a bone marrow transplant. For young Philip, however, it was
too late. He had surgery for MLD in December 1991 and died
in the summer of 1992. Had an MRI been prescribed without
undue delay, chances are the boy would still be living.
Neurologists are just one medical specialty
that depend a great deal upon MRI for accurate diagnostic
information. Other medical specialties and healthcare providers
that rely in great numbers upon MRI include neurosurgeons,
orthopedic surgeons and chiropractors. Because MRI portrays
soft tissue with such diagnostically-useful clarity, it is
relied upon frequently for revealing abdominal abnormalities-mid-field
scanners are clearly superior to high-field scanners in this
regard-and a wide variety of other ills as diverse as malfunctioning
temporomandibular joints (TMJs) in the jaw, pinched nerves
in the spinal column, heart disease and multiple sclerosis.
(Nothing is superior to MRI for revealing MS.) From the beginning,
of course, one of the great strengths of MRI has been its
ability to reveal tumors.
Incidentally, don't let the fact that
MRIs provide great soft-tissue imaging mislead you into thinking
that they aren't great for many types of musculoskeletal imaging.
In fact, the second largest application for MRI at present
is musculoskeletal disease. Orthopedic physicians regularly
refer patients for MRIs for a wide variety of conditions.
That's why you hear so much, for example, about professional
athletes getting MRI scans. FONAR has been a pioneer in the
development of a number of specialized MRI diagnostic methods
used in sports medicine. It has led the way, for example,
in providing anatomical motion studies. These studies enable
technologists to electronically sequence a series of MRI images
to create an accurate portrayal of how a malfunctioning joint
in a patient is working dynamically. Individual MRI images
reveal static conditions, just as a photo snapshot reveals
a person's likeness just for an instant of time, but misses
the facial expression that occurred a second or two earlier
and the one that followed immediately after. A dynamic portrayal
of a joint helps a physician understand how a particular joint-a
shoulder, a knee, a neck or a TMJ-functions in "real
life." Incidentally, open-environment MRI scanners such
as FONAR manufactures are clearly superior for these motion
studies as they provide the space required for a patient to
move their arm, leg or neck through a wide range of positions.
Magnetic resonance angiography (MRA) is a well-utilized procedure
that will only increase in use by cardiologists in the future.
Although CAT scans are better able to show calcified plaque
that has built up in an artery, physicians will increasingly
turn to MRA in the future to reveal the presence and severity
of soft atherosclerotic plaque. In other words, it will reveal
newer, more recent plaque which has formed, enabling physicians
to view the extent of artery disease more accurately and to
treat that disease more appropriately. Incidentally, patients
who require life-support systems-heart patients, for example-can
be imaged in a FONAR MRI scanner. Although more and more non-magnetic
devices are being developed for use around "supercon"
scanners with large fringe fields, normal life-support systems
with ferromagnetic components have been used around FONAR
scanners for years because of their vertical magnetic fields.
Nothing is superior to an MRI for imaging breast implants.
It shows the implants much more clearly than other modalities
and it has the added advantage of not using X-rays, a particular
concern when imaging the breast. MRI is also superior to ultrasound,
X-ray mammograms or CAT scans when it comes to revealing malignancies
in very dense breasts. This is still a developing area for
MRI, one which will become much more dominant in the future.
The MRI applications mentioned above are just a small portion
of the applications for which MRI is the modality of choice.
If you have further questions, discuss them with your physician
or speak with a radiologist who specializes in MRI. MRI is
still a developing modality whose diagnostic power is becoming
more and more appreciated with time. Already, it has replaced
a great number of X-ray-based procedures and it is certain
to replace even more in the future.