Medical Ultrasonography: Tracing Bask Its Roots
Medical ultrasonography is a diagnostic imaging technique that uses ultrasound equipment. Ultrasonography is utilized to visualize the size, structure, and pathological lesions of internal organs. The following is a brief overview of the history and modern applications of medical & diagnostic ultrasonography.
Ultrasonography was invented in 1953 at Lund University by cardiologist Inge Edler and Carl Hellmuth Hertz, a graduate student studying nuclear physics. Edler had asked Hertz if it was possible to use radar to look into the body. Hertz said it was impossible, though there might be a possibility via ultrasonography. Hertz was familiar with using ultrasonic reflectoscopes for nondestructive materials testing; together they developed the idea of using this method in medicine and ultrasonography was introduced to the world.
Using a device borrowed from a ship construction company in Malmö, Sweden, their first successful measurement of heart activity was made on October 29, 1953. On December 16 of that year, their method was used to generate an echo-encephalogram, an ultrasonic probe of the brain. Edler and Hertz published their findings in 1954.
Meanwhile, Professor Ian Donald and colleagues at the Glasgow Royal Maternity Hospital in Scotland conducted the first diagnostic procedures using ultrasonography. Donald was an obstetrician who had used industrial ultrasound equipment to conduct experiments on morbid anatomical specimens to assess their ultrasonic characteristics. Together with physicist Tom Brown and Dr. John MacVicar, Donald refined the equipment to enable differentiation of pathology in live patients. These findings were published June 7, 1958 as "Investigation of Abdominal Masses by Pulsed Ultrasound"; one of the most important ever papers published in the field of diagnostic medical imaging.
Professor Donald and Dr. James Willocks then applied these techniques to obstetrics to assess the size and growth of the fetus. As technical quality of the scans was further developed, it became possible to monitor pregnancy from start to finish and diagnose complications such as multiple pregnancy and fetal abnormalities. Diagnostic ultrasonography has since been utilized in many other areas of medicine.
Today, medical ultrasonography is used in:
- Cardiology
- Endocrinology
- Gastroenterology
- Gynecology
- Obstetrics
- Ophthalmology
- Urology
- Anesthesia
Modern diagnostic ultrasonography uses a probe containing one or more acoustic transducers to send pulses of sound into a material. Whenever a sound wave encounters a material with different acoustical impedance, the probe detects an echo. The time it takes for the echo to travel back to the probe is measured and used to calculate the depth of the tissue.
The sound frequencies used for medical ultrasonography are generally in the range of 1 to 10 MHz. Higher frequencies have a lower wavelength, producing images with a greater resolution. However, the attenuation of the sound wave is increased at higher frequencies, so in order to better penetrate deeper tissues, a lower frequency (3-5MHz) is be used.
The value of ultrasonography in healthcare facilities weighs heavily on its multi-functionality. It produces images of muscle and soft tissue, useful for delineating boundaries between solid and fluid-filled spaces. It provides live images, enabling operators to select the most useful sections for diagnosing and documenting changes for rapid diagnoses. It shows the structure and function of internal organs. It’s a useful way to examine the musculoskeletal system to detect problems with muscles, ligaments, tendons, and joints. It also assists in identifying blockages, stenosis, and other vascular abnormalities. With such wide-ranging benefits, the modern medical facility is at a severe loss without the most technologically advanced equipment.
