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An x-ray is a commonly
ordered, first-line diagnostic test where low dose of radiation
passes through the body to produce a single black and white image.
This test is best used for looking at the bones for fractures or
other abnormalities, and for other areas in the body with contrasts
in the densities of the tissues like the chest or the abdomen.
X-ray pictures are often taken in a variety of positions of the
desired area to get a full understanding of how the body’s
structures are relating to one another. No preparation is required
for this test, but x-rays should be avoided by pregnant women.
CT
A CT scan is a special
type of x-ray where multiple low-dose x-rays are taken in sequence
or “slices” by rotating a x-ray tube around your body. A computer
turns the “slices” into a composite image. This diagnostic test is
used to detect injuries, inflammations, or other abnormalities of
the soft tissues or other internal organs. The results of the CT are
interpreted by a radiologist, and the results are shared with your
physician. Most CT scans ordered in the orthopedic setting require
no prior preparation or contrast material to be ingested.
MRI
A MRI scan is a highly
advanced imaging technique that uses a magnetic field and radio
waves (instead of radiation) to create multiple cross-sectional
views of the internal body structures. Internal organs, muscles,
cartilage, ligaments, tendons, bones, nerves, and even blood flow
can be seen on a MRI scan. The scan takes 30 to 60 minutes and
requires that you lay as motionless as possible while a circular
tube passes over your body or the area to be tested. If you are
claustrophobic, an “open” MRI machine can be used. The results of
the MRI images are interpreted by a radiologist, and the results are
shared with your physician.
Most MRI scans ordered in
the orthopedic setting require no special preparation, however,
patients who have any type of metal implants in their body might be
contraindicated for this exam as the metal might interfere with the
picture created by the magnetic field. Metal in the body might
include the presence of a pacemakers, artificial valve, metal
“hardware”, insulin pump, IUD birth control device, inner ear
implant, or brain aneurysm clip. In addition, patients who are
pregnant, have a history of gun shot wound or a similar injury, or
have been metal workers in the past might be contraindicated to have
an MRI.
Ultrasound is a procedure that bounces high-frequency
sound waves off an area to be examined and captures the returning
“echoes” as images. Ultrasounds have significantly improved over
the years in their diagnostic capabilities, and these tests are now
used for a variety of body areas including the thyroid, heart,
pelvis and abdomen, kidneys, and pregnancy. In the orthopedic
setting, ultrasounds can be used to detect the presence or absence
of blood flow in the legs if a blood clot is suspected. No prior
preparation is required for this test.
ARTHROGRAM
An arthrogram is an injection of a non-radioactive
iodine contrast and a small amount of air directly into the joint
space. X-ray pictures of are taken of the joint space in various
positions. This test is often used to better determine the
character of the joint space, looking for evidence of arthritis (as
in the case of the hip), loosening of a prosthesis (as in the case
of a total joint replacement), or even tendon damage (such as a
rotator cuff tear in the shoulder).
Myelogram
Like an arthrogram in
technique, a myelogram refers to the injection of non-radioactive
iodine contrast material into the spine to detect spinal problems
such as stenosis or disc herniation.
BONE SCAN
A bone scan is a more
lengthy procedure and involves two parts. First, a small amount of
radioactive material is injected and allowed to work its way through
the bloodstream to be absorbed by the bones. After the injection,
the waiting period is approximately three hours. The actual scan
takes place after this time and detects any areas of uptake,
producing a series of pictures that are used to detect bone growth,
suspected fractures that are difficult to see on regular x-rays,
tumors or infections. No preparation is required for this test, but
bone scans should be avoided by pregnant women.
An EMG is a two-part test
that measures the electrical activity of muscles and nerves, usually
in an extremity. In the first part of the test (called the nerve
conduction study), electrodes are placed on the skin of the
affected extremity that deliver small, short shocks of variable low
level electrical current while electrical response of your muscles
is measured on a computer. In the second part of the test (called
the needle examination), a tiny coated needle is inserted
into one or more muscles and you are asked to relax and contract the
muscles and a computer measures your muscle or muscles’ electrical
activity. Results from both parts of the test are analyzed together
by a neurologist help to distinguish between conditions that arise
from problems in the nerves or problems with the muscles. The test
takes from 30-60 minutes and only mild discomfort can be expected.
No preparation is required for this test.
In orthopedics, the most
common reason for ordering laboratory tests is to test for the
presence of infection, and possibly other inflammatory process such
as gout or rheumatoid arthritis. Other important tests might be
used after significant surgery, such as to monitor the level
hemoglobin in the blood to make sure the red blood cells have enough
capacity to carry oxygen to the vital tissues.
The body can be analyzed
in a variety of ways to test for the presence of infection. General
blood tests that might indicate there is some inflammatory or
infectious process in the body include a white blood cell count (WBC),
c-reactive protein (CRP), and/ or the erythrocyte sedimentation rate
(ESR). When a wound or fluid collection in the body is thought be
infected, a culture might be done to determine which exact bacteria
is the causative organism or if there are crystals present that
might indicate gouty arthritis. The culture can also be analyzed as
to which antibiotic medication will be effective in treating the
infection. Other tests might be recommended in order to determine
the source of the infectious process, including blood cultures or
urinalysis. |
