Diplomate, Board Certification of Emergency Medicine
Chairman, Department of Emergency Medicine Ma'ayenei Hayeshua
Hospital
MUGA, CT, MRI, Flor, Echo, Thallium, Sestamibi, VQ,CXR,
Angio. Most people are not familiar with the above words and
abbreviations, but there are all tests that are done with our
new technology in the field of radiology.
X-rays were discovered in the nineteenth century by Wilhelm
Roentgen. He discovered that, depending on the density of the
material, pictures taken of things with a form of radiation
produced different figures on photographic paper. In a
person, air is deep black, fluid and tissue are white, and
bone is deep white. This helps us not only find fractures of
bones, but tells us about obstructions in abdomens,
pneumonias and heart failure in the chest and masses on
mammography.
One X-ray is very safe. One of my favorite stories is about a
child who swallowed the nose of his teddy bear. In the
emergency room, they brought his sister's bear (it was the
same type), X-rayed its nose and then the little boy. In the
end they found that bear's noses do show up on X-rays, but
the boy had not swallowed it.
X-rays do not pick up everything. Gall bladder stones for
example often don't show up on X-rays. Babies in their
mothers wombs may be damaged by X-rays. Some parts of the
body are hard to reach with X-rays, such as the prostate and
the female organs. X-rays don't tell us anything about blood
flow and clots.
Enter ultrasound. This works like a bat's natural equipment --
it bounces sound waves off an object and then recovers them.
Based again on the density of the object, the sound waves are
bounced back at different frequencies. Sound waves are
everywhere, so the safety of ultrasound is unquestioned. It
is cheap and available.
However, the detail one gets with ultrasound isn't always the
greatest. I don't know who it was, but someone came up with
the idea of taking many X-rays of the same body part from
different angles, and then reconstructing the images with a
computer. The detail was remarkable. This was the birth of CT
scanning. It has revolutionized the diagnosis of stroke and
trauma, and evaluates the abdomen and chest as well as the
head in ways normal X-rays can't even come close to.
Naturally the load of radiation is high, but this test is the
most available and gives the most information.
MRI is the newest modality. It doesn't even work on radiation
but rather magnetism. The detail is even better than CT, but
it is very expensive. With the exception of spinal cord
disorders, other tests should be done first. Be careful! Your
magnetic strip cards, such as credit cards, can be affected
in an MRI building.
Nuclear medicine is a field where a radioactive chemical is
injected into the blood stream, and a Geiger counter is waved
over the body to see where the radiation is picked up in the
body. It is safer than it sounds. These chemicals have very
short lives in the body and they quickly become non
radioactive. They mainly help in heart scans, such as stress
tests, and in bone and lung scans.
The technology is amazing, and takes a lot of guesswork out
of medicine. Still, going for these specialized exams can be
time consuming, occasionally claustrophobic and expensive.
Nevertheless they are for the most part safe and can make a
difference. Write me in care of the Yated.
