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Authors: Dr. Suraj Agarwal

INTRODUCTION

Dr. Karl Theo Dussik, an Austrian neurologist, was the first to apply ultrasound as a medical diagnostic tool to image the brain.Today, ultrasound (US) is one of the most widely used imaging technologies in medicine. It is portable, free of radiation risk, and relatively inexpensive when compared with other imaging modalities, such as magnetic resonance and computed tomography. Images are tomographic, i.e., offering a “cross-sectional” view of anatomical structures. The images can be acquired in “real time,” thus providing instantaneous visual guidance for many interventional procedures including those for regional anesthesia and pain management.

Diagnostic ultrasonography is the study of tissues of the human body with the utilization of reflections (echoes) of high frequency sound waves (ultrasounds) which are introduced on the body surface, in the area under examination, by a device called transduer. A special kind of crystal located in the transducer will vibrate when stimulated by electricity.Transducer generates high frequency sounds through a process known as “piezoelecriceffect”.Consequently, an ultrasound transducer converts an electric signal into mechanical motion into ultrasound.
 

HISTORY:

1790, LazzaroSpallanzn, bats navigated their way through the use of ultrasonic waves and echolocation.

1826, Swiss physicist Jean Daniel Colladon discovered Sonography, using an underwater bell (speed of sound under water).

1881, Curie brothers found a  Piezoelectric crystal converting mechanical energy into electrical.

Paul Langevin invented the first transducer by making the hydrophone which could  send &receive low frequency sound (submarine detection in World War I)

1930 Dr Karl Dussik, Australian psychatrist, procedure Hyperphonography, using heat sensitive papers recorded echos.

1940, Dr George Luwig record the differences in sound travel through various tissues and noted the principle of impedence.

 Ian Donald, designed devices using this info, for monitoring pregnancy, in 1950 used this equipment with sonar background to find an ovarian cyst- FATHER OF OBSTETRIC ULTRASOUND . Also invented the B-mode scanner, able to detect a twin pregnancy.

1950-60 D Howry, J Holmes improved B-mode scanner. Patient had to be submerged in water to produce images, invented a Transducer that was put in direct contact with the patient.

 J Wild, J Reid produced a Hand held B-mode instrument that could swing side to side and get cross views from various angles.

First reference to use of intraoral ultrasound probe was by Keller in 1976.

The first use of ultrasound to identify and locate a parotid calculus was recorded by Pickrell in 1978.

3D ultrasound was first developed by Olaf von Ramm and Stephen Smith at Duke University in 1987

 
 
 
 
 
 
 

 

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