History of Thyroid Ultrasound

Abstract

Ultrasound technology evolved following World War II as an outgrowth of the research used in developing radar. Subsequently it was introduced into medicine in the early 1960’s. I recall first using an ultrasound machine in 1965 as an intern in the emergency room of Grady Memorial Hospital in Atlanta. Its purpose was to examine patients who had undergone head trauma to detect a possible “pineal shift”, diagnostic of a subdural hemorrhage. With this early “A-Mode” (amplitude mode) ultrasound, the sound waves from the transducer placed behind the patient’s ear were reflected as echoes or vertical spikes along a horizontal axis on a Cathode Ray Oscilloscope screen. These spikes indicated the temporal bone plates on each side of the skull. If the pineal gland was calcified, it also produced a spike midway between the other two spikes. While this method was no more accurate than a x-ray of the skull, its advantage was that it could be performed by the examining physician, and provided a more rapid diagnosis in an emergency situation. A “pineal shift” of one centimeter or more would prompt a call to the neurosurgeon.