erdenejargal ct history
DESCRIPTION
Slide presentation for the history of the modern CT scanner.TRANSCRIPT
Topic: 4. Developments in Medical CT Equipments
Tuya Erdenejargal
APPM 4380September 14, 2015
Word Origin
CT Scan
Computed Tomography (CT) orComputed Axial Tomography (CAT) scanning
Tomography = Tomos + graphia (Greek)
Tomos means ”slice” or ”section”graphia means ”describe”
Types of CT Scan
Depending on the type of emission
• X-Ray CTMost common. 72 million scans were performed in the United States (2007)
• Positron Emission Tomography [PET]
• Single-Photon Emission Computed Tomography [SPECT]
Why CT Scan?
Tradition X-Ray Image
• 1895 (William Roentgen)
• First non-invasive tool
• 3D reduced to 2D :(
CT Image
• 1970s
• Cross-section of body parts
• More contrast in the soft tissues
Nobel Prize 1979
The Nobel Prize in Physiology or Medicine 1979 was awarded jointly to Allan M.Cormack and Godfrey N. Hounsfield ”for the development of computer assistedtomography.”
The First Commercial CT Scanner
Very first scan
1971, Atkinson Morley Hospital,London, UK- Cerebral cyst patient
The First Commercial CT Scanner
• Widely installed between 1974 and1976
• Only for head imaging
• Whole body scan by 1980
Now 6000 CT scanners installed in theU.S. and about 30,000 installedworldwide.
Improvement
Brain Image
Circa 1975, in the early days of the CTscan
A present-day scan, showing the six-foldincrease in detail
Improvement
SpecificationFirst CT Scanner(circa 1970)
State-of-The-Art
Time to acquire image 5 minutes 350 ms
Pixel Size 3 mm x 3 mm 0.5 mm x 0.5 mm
Number of Pixels inImage
80 x 80 512 x 512
Principles of CT Scanning
Johann Radon (1887-1956) Radon Transformation
Image of an unknown object could beproduced given an infinite number ofprojections through the object.
Principles of CT Scanning
Radon Transformation in Medical Imaging
M(r , θ) = The total attenuationµ(x , y) = The attenuation map
M(r , θ) =
∫ ∞−∞
µ(x , y)ds
RM(r , θ) = µ(x , y) ,
where R is Radon Transformation.
Principles of CT Scanning
Principles of CT Scanning
Principles of CT Scanning
Principles of CT Scanning
Principles of CT Scanning
Evolution of Different CT Scanners
Research and Development
Types of RD
• Increase Resolution
• Decrease Radiation Dosage
• Decrease Cost
Reference
• http://www.physicscentral.com/explore/action/scans.cfm
• http://pathology.jhu.edu/pc/ctscan.php
• http://www.nobelprize.org/nobelprizes/medicine/laureates/1979/http ://www .imaginis.com/ct − scan/brief − history − of − ct
•• http://thatsmaths.com/2013/03/07/ct-scans-and-the-radon-transform/
• http://www.impactscan.org/slides/impactcourse/basicprincipleso fct/img8.html