2. Presentation Overview
General ultrasound method
Comparison between ultrasound and x-ray
History
Various uses
Physics of the method
Current state
Continuing technology
Conclusion
3. General method
Place small transducer against the skin
Emits high frequency sound waves
Detects bounce back waves
Differenttissues reflect different waves
Reconstruction software
Viewing structure on a screen
4. Diagnostic Ultrasound X-rays
(radiology)
wave type longitudinal mechanical electromagnetic
waves waves
transmission elastic medium No medium
requirements
generation stressing the medium accelerating electric
charges
depends on the medium
velocity It is relatively constant:
through which it
299,792.456.2 m/s
propagates
similar waves seismic, acoustic radio, light
5. Discovery
History
High frequency (“ultrasound”)
Lazzaro Spallanzini, 1794
Bats navigation
Francis Galton
Galton whistle (above audible frequency)
Gabriel Lippman, 1881
Reciprocal behavior of achieving a mechanical stress in
response to a voltage difference was mathematically
deduced.
Generation and reception of ‘ultrasound’
6. History
First use of diagnostic ultrasound
Dr.Karl Dussik, 1942
Locate brain tumors
Two devices
Emitter and reciever
7. Physics of the Method
Longitudinal mechanical waves
Needs elastic medium
Transducer needs to be in contact with skin
Component resolution
3 MHZ ->1.1 mm
10 MHZ -> .3 mm
Wave velocity
Fat -> 1450 m/s
Muscle ->1580 m/s
8. Various Uses
View soft tissue
Heart
Pelvis and reproductive organs
Kidneys, liver, pancreas, gall bladder
Eye
Thyroid
Blood vessels
Fetus
12. Continuing Technology
Color Imaging
Quantum computing
Detection of more tissues
Better transducers (ie. Higher resolution)
More readings
Better breast cancer detection
Can decypher between a malignant mass and a benign cyst.
Painless and safe compared to mammography
16. Conclusion
Ultrasound is an important medical imaging
mechanism
Non-invasive
Powerful
Cheap
17. References
“Medical Procedures”,Imaginis Corporation. Updated 10 November 2000.
This document is http://imaginis.com/ultrasound/
“High Definition Three-Dimensional Ultrasound”, University of
Cambridge. This document is http://mi.eng.cam.ac.uk/~gmt11/hd3dus/
“History of Ultrasound in Obstetrics and Gynecology”, Woo, Joseph. This
document is http://www.ob-ultrasound.net/
“3D/4D Ultrasound: State-of-the-Art Technology”, Greater Pittsburgh
Ob/Gyn &Mercylink. This document is
http://www.expectantmothersguide.com/library/pittsburgh/ultrasound.htm
“Telemedicine”, Dr. G Diaz. This document is http://www.drgdiaz.com