Module 1: Historical Development Flashcards
word sonography means
Latin word SONUS (sound) and Greek word GRAPHIEN
(to write)
Anatomic imaging with an ultrasound is accomplished with
Pulse-echo technique
sent into the tissues to interact with them. Echoes return from the tissue providing information that is useful for anatomic imaging.
UTZ pulses
both generates and detects the returning echoes. The ultrasound instrument processes the echo formation and generates appropriate dots, which form the ultrasound image on the display.
Transducer
Backbone of any ultrasound device
Transduceer
Advantages of Sonography
- Mobility
- More cost effective
- More versatility
- MInimal supplies
Animal World
Audible Range of Elephants, and Whales
0.1-25 Hz (infrasound)
Animal World
Audible Range of Humans
20 - 20,000 Hz or 20 KHz
Animal Word
Audible Range of Dogs
Up to 40,000 Hz
Animal World
Audible Range of Cats
100 to 60,000 Hz
Animal World
Audbile Range of Dolpins
1,000-100,000 Hz or 100 KHz
Animal World
Audible Range of Bats
Up to 150,000 Hz or 150 KHz
Locations are identified through soundwaves being reflected and bounced back
Echolocation
Historical Perspective of Sound
1st provide experimental evidence that non-audible sound exist around us
Lazaro Spallanzani
Historical Perspective of Sound
In 1794, Spallanzani hypothesized that bats navigated using?
sound waves
Historical Perspective of Sound
- used underwater church bell
- proved sound travelled faster through water than air
Jean Daniel Colladon (1826)
Historical Perspective of Sound
- Hypothesized that the pitch of a sound would change if the source of the sound was moving
Christian Andreas Doppler (1803-1853)
Historical Perspective of Sound
an important tool in ultrasonography today
Color doppler ultrasound
Historical Perspective of Sound
discovered the “Piezo-Electric Effect” in certain crystals
Pierre and Jacques Curie (1880)
Historical Perspective of Sound
led to the development of the ultrasound transducer
Pierre and Jacques Curie (1880)
Historical Perspective of Sound
the backbone of any ultrasound device
Transducer
Historical Perspective of Sound
what is the first transducer called?
Hydrophone
Historical Perspective of Sound
invented the hydrophone after Titanic sinking (1912) to detect icebergs and submarines during WWI
Paul Langevin (1915)
Historical Perspective of Sound
First physician to use ultrasound for medical diagnosis (of brain tumors)
Karl Dussik (1942)
Historical Perspective of Sound
First described the use of ultrasound to diagnose gallstones
George Ludwig, MD (1948)
Historical Perspective of Sound
Continued to use through-transmission techniques and computer analysis to diagnose brain lesions in the intact skull but discontinued after concluding the techniques is too complicated for routine clinical use
Dussik, Heuter, Bolt and Ballyantyne (Early 1950s)
Historical Perspective of Sound
Developed the first ultrasound scanner consists of a cattle watering tank with a wooden rail anchored along the side.
The transducer carriage move along the rail in a horizontal plane, while the object to be scanned and the transducer was inside the water tank
Howry (1948)
Historical Perspective of Sound
Echocardiographic techniques were able to distinguish normal heart valve motion from a thickened, calcified valve motion seen in patients with rheumatic heart disease
Hertz & Edler (1953)
Historical Perspective of Sound
first successful echocardiogram
Hertz & Edler (1953)
Historical Perspective of Sound
Pioneer 2D B-mode ultrasound at the University of Colorado
Douglas Howry & Joseph Holmes (1950S)
Historical Perspective of Sound
Early obstetric contact-compound scanner used primarily to evaluate the location of the placenta and to determine the gestational age of the fetus
Tom Brown & Ian Donald (1957-1958)
Historical Perspective of Sound
Pioneers OB-GYN ultrasound
Ian Donald (1958)
used in clinical medicine has not been associated with any harmful biologic effects and is generally accepted as a safe modality
Diagnostic ultrasound
Diagnostic ultrasound uses ____ to generate an image of a particular structure in the body
non-ionizing, high frequency sound waves
- used for calculation of blood flow velocities
- detection, quantization and evaluation of tissue motion and blood flow
Doppler technique
are clinically useful in determining direction, resistance, turbulence or regurgitation of blood flow
- Pulse-wave
- Continuous flow
- Color-flow mapping
Nature of Ultrasound
A form of energy of mechanically produced waves and frequencies above the range of human hearing
Ultrasound
Nature of Ultrasound
Ultrasound is a sound with a frequency greater than?
20,000 Hz or 20 KHz
Nature of Ultrasound
Unit of frequency
Hertz
Nature of Ultrasound
Indicates the number of wave cycles that passes
Hertz
Nature of Ultrasound
the first ultrasound instrument emitting frequencies above 20,000 Hz
Dog Whistle
uses frequencies ranging from 1-10 million Hz (10 MHz)
Diagnostic Ultrasound
Diagnostic Ultrasound
below 20 Hz
Infrasound
Diagnostic Ultrasound
20 - 20,000 Hz
Audible Sound
Diagnostic Ultrasound
above 20,000 (16,000 - 20,000 Hz)
Ultrasound
Diagnostic Ultrasound
1,000,000 - 20,000,000 Hz (1- 20 MHz) or 2,000,000 - 12,000,000 Hz (2-12 MHz)
Diagnostic Ulrasound
unsucessful attempt at locating the Titanic which sank in 1912
Industrial Application
SONAR
Sound Navigation and Ranging (WWII)
Medical Applications
1st practical ultrasound imaging unit was designed by and when?
Karl Dussik (1949)
Medical Application
constructued the 1st B-mode scanner from surplus naval sonar equipment, an oscilloscope and a quartz transducer
Douglas Howry and W.R. Bliss (1949)
Medical Application
constructed the 3rd B-mode scanner from a B-29 gun turret
Joseph Holmes and Douglas Howry
Medical Application
3rd B-mode scanner
Sonoscope
Medical Application
1st contact static B-mode scanner commercially manufactured by?
Physonics (1960)
What are the two Biological Effects?
- Heat (Thermal Effect)
- Cavitation (Mechanical Effect)
Effect created by vibrating motion of vibrating molecules
Heat (Thermal effect)
results in an attenuation of the ultrasound beam and absorption of energy by the target tissue results in elevation of temperature
Vibration
Temperature elevation is not an instantaneous phenomena because of?
Physiologic protective measure of the body by
- Thermal Conduction (from cell to cell)
- Thermal Convection (way of body fluids)
In Diagnostic Ultrasound, Temperatures rise up to?
0.1 degrees Celcius or less (considered safe and not a significant biologic hazard)
Violent molecular agitations can result in?
Microbubbles
occurs when dissolved gases grow into bubbles around stable microbubble nuclei during the negative pressure phase of the propagated sound wave
Cavitation
Intensities greater than approximately ________ are necessary for the formation of microbubbles
1000 W cm -2
very short pulse lengths associated with pulse-echo ultrasound will not produce?
Cavitation
have not been confirmed for pulse ultrasound intensities less than 100 mV/cms
Bioeffects