Thompson Uses Sound to 'Get the Picture'

              SHREVEPORT JOURNAL, Tuesday PM Your Health SHREVEPORT BOSSIER CITY, LA., DECEMBER 2, 1980
Thompson Uses Sound to 'Get the Picture
By LESLIE WATKINS
Journal Staff Writer
Ultrasound, a technique used by doctors
in order to see inside a patient's body —
with sound and not radiation — is not new
or unique to Shreveport, but one local
doctor knows all about it.
Dr. Horace E. Thompson, who came to
Shreveport two-and-a-half years ago to
teach and head the department of ob-stetrics
and gynecology at LSU Medical
Center, has been involved in the field of
ultrasound — use of high frequency sound
waves to identify and visualize structures
within the body — for the past 20 years.
The recipient of the William Fry Memo-rial
Award in 1978 for contributions to the
use of ultrasound in medicine. ThomDSOn
spent many years in Denver. Colo., where,
at the University of Colorado, pioneering
work in the field of ultrasound took place.
"With ultrasound we can follow any
structure, actually visualize it with sound
waves," Thompson explained in a recent
interview. Original work was in the field of
obstetrics, he added, but new techniques
and equipment are being developed every
day .as well as new areas of medical
application. (Thompson's book, "The Use
of Ultrasound in Obstetrics," is only two
years old, but he's quick to tell you it needs
revision.)
In pre-natal care, ultrasound is used to
reveal a baby's form, activity and move-ment
within the mother. The cross-sec-tional
picture may not be clear to the
expectant mother, but to the doctor the
fetal form is clear: head, trunk and ex-tremeties,
its heart beat and organs.
By looking directly at the organs, the
doctor can determine how they are de-veloping
and then monitor their develop-ment
throughout pregnancy by taking ac-tual
photographs of the fetus and keeping
them on file.
Also used to detect brain lesions, eval-uate
heart conditions and to determine the
size, shape and extent of tumors (and how
effective various types of therapy have
been against them), ultrasound is a great
diagnostic tool, Thompson said.
Ultrasound served in military and in-dustrial
capacities before emerging into
medicine, Thompson said, but its basic
technology was discovered in the 16th
Century when it was determined that bats
detect objects by sound, not sight.
In 1880 — 15 years before the develop-ment
of x-rays — researchers found that
there are crystals in nature which, when
high frequency sound waves travel across
them — actually convulse; it was later
discovered that these crystals could both
receive and transmit high frequency sound
waves.
During the 19th Century, industry be-
Dr. Horace Thompson of the LSU Medical Center stands before the hospital's Ultrasound machine which uses
high frequency sound waves to transmit an image of an internal part of the human body onto the small television
screen. (Journal photo by Stan Alost)
came interested in using ultrasound to
detect flaws in metals. Instead of breaking
up the long sheets of ore, high frequency
sound waves were transmitted across
them; any flaw reflected an echo.
In World War I the French tried to use
sound waves to detect submarines, but
that conflict was over and another begun
before sonar was actually used to detect
underground vessels; today, sound wave6
are used to find schools of fish, sunken
ships and other large forms beneath tftfi
ocean. «*;.;
Out of industrial and military uses two
individuals developed ultrasound for use in
medicine, Thompson said. Douglas How-rey
("a year ahead of me in medical
school") of the University of Colorado
developed its use for the human body aftd
J. J. Wyld in Minnesota introduced it as a1
diagnostic testing procedure.
Thompson said he got involved in de-veloping
the use of ultrasound in obstetrics
in 1960 at the University of Colorado
during which time complementary work
was being performed by Ian Donald in
Glasgow, Scotland.
Since sound does not travel well in air ~
and won't travel at all in a vacuum —a
coupler is necessary for the sound to
transmit an image onto the screen.
Thompson likes to use a water soluble
acoustic jelly ("because it isn't sticky"),
but mineral oil is used as well.
The coupler is spread across the section
of the body the doctor wants to examine
and then the crystal transmits and fie:
ceives the high frequency waves to create
the image. "In obstetrics, we usually uAr
in the million to 20 million vibrations per
second range," Thompson said, "but any-thing
over 20,000 vibrations per second is
considered ultrasound."
Thompson said they do not think there is
any danger in using sound waves because
20 years of research projects has revealed
no evidence of harm. However, because
sound waves do not travel through air,
they pose no threat to anyone near the
patient.
B