ch 14-16 Flashcards
Decision making of the CPU;
Evaluated an immediate response
Logic function
The microprocessor of the computer
Is the CPU (central processing unit)
A device that demonstrates signals to convert digital to analog through a phone line
Modem
Device used to produce alphanumeric characters
Character generator
A string of 8 bits
A Byte
The computer program that organizes the course of data thru computer such as DOS, Windows, MAC)
Operating system
An initial program to wake up the computer (power on)
Bootstrap!
Specific computational program or formulas and equations
Algorithms
Early mathematic computer program. That Microsoft developed into a powerful programming language
BASIC
Data to be accessed at random from anywhere
RAM
Random access memory
Hardware vs software
Hardware you can see(nuts n bolts of computer) software are the programs that operate the computer
Kinds of hardware
Input output divides, memory sticks, microprocessor
A single binary digit
8 bits
2 bytes
Binary
Byte
Word
____________ runs the computer
______________ runs the data.
System software
Application programs
What computer language was the 1st successful computer language ?
FORTRAN
What is teleradiology
Practice where radiologists remotely read exam results
What is one kB (kilobyte)
1024 bytes
A photostimulable phosphor (PSP) bound in a cassette is an image receptor
Imaging plate
What is used as the activator in a photostimlable phosphor? Or latent image center in CR
Eu) europium
The time varying analog signal from the photodetector is processed and digitized with attenuation by
Signal sampling
An electron excited energy state beyond its normal orbital state
Metastable electron
A broad spectrum of wavelengths (colors) of visible light
Polychromatic
The rapid manner in which the laser beam is swept across the imaging plate
Fast scan
Electrons raised to an exited state by X-ray exposure return to ground state with an immediate emission of light
Prompt emission
A phosphor barium flourohalide, where electrons are not released to the ground state until light is emitted.
Storage phosphor
The white appearance of phosphor particles bcuz of their small size
Turbid
A silicon solid state device sensitive to light.
Which converts light into electrical signal !!
Photodiode
How is the latent image formed in CR
Electrons are energized by X-ray interaction into excited metastable energy state.
What causes the phitostimulable phosphor plate to appear turbid??
The small size of crystals causing them to scatter incident light
How do we reduce backscatter in CR ?
The imaging plate is backed with Lead to absorb the scatter radiation. Which causes noise on the image
What are the colors for
Emitted light?
Stimulating light?
Emitting= blue/green Stimulating = red/orange
What is the purpose of an optical filter positioned before the photodetector ??
To absorb any scattered long wavelength laser light !!
What is slow scan??
The mechanical drive of the imaging plate through the reader
What is a buffer??
A temporary storage place (usually a hard disk)
Why is beam shaping required for laser beam ??
To ensure the beam interacts with the IP, it remains as a circle, not to distort into an ellipse
3 subsystems of CR
Mechanical drive system
Optical beam shaping
Collecting system
How is ghosting reduced??
Additional erasing in the CR reader!
Whats the difference, if any-of prompt emission and stimulating emission??
They have the same wavelength
How is the latent image made visible on CR??
By stimulating the metastable electrons with an intense beam of laser light!!
What does the activator eU do to electrons??
It is responsible for trapping electrons in a metastable state.
What is the parallex effect??
Image edges that are out of tolerance are called??
Penumbra
Wavy
4 characteristic of any medical image
Spatial resolution
Contrast resolution
Noise
Artifacts
How many levels of gray does CR have?
Old film have?
100,000 shades
30 shades
Cr image contrast is _________
Regardless the radiation exposure
Constant!
What is SPR??
Scanned projection radiography
Which is the use of a fan X-ray beam to form a radiograph
What is amorphous?
What is spatial resolution ?
Not crystalline in form., rather a paint of crystals
Ability to render very small high density objects visible on image
Where is fan X-ray beam used??
In CT and SPR
A solid state system that converts light to electrical signal w high resolution
Charge-couple device
What do scintillation phosphors do??
Phosphors such as (NaI, CSI) Emit light in response to X-ray
DMIST??
Associated with American college of radiology to see if mammography was equal to screen film
Dynamic range ?
Several projection radiographs from different angles in digital form ??
The number of grey levels on image
Tomosynthesis
How does pixel size incCCD DR compare of other DRs??
CCD is smaller pixels
Why is fill factor important??
In DR, the smaller the pixel, the less fill factor..
Low fill factor = higher patient dose
What is sensitivity in DR??
Is how low an X-ray intensity can be detected for imaging
What are the stages for a-Se based DR of the following:
Capture=
Coupling=
Collection=
Selenium
Selenium
Thin film transistor
What does the coupling element do??
Transfers the X-ray generated signal to collection element
What is a collection element ??
May be a photodiode, a CCD, or thin film transistor
BUS stands for ?
Th Connector OR electrical conductor
Between the CPU and ALU
1/2 byte =
Two words=
Nibble
Chomp
What is DICOM??
Digital imaging and communications in medicine
Standard method in image storage!
Th most popular programming language and is a high level general purpose program
PASCAL
5x faster than the basic modems
ISDN
What is CRT??
Cathode ray tube — vacuum tube in computers
________ scan is vertical on IP
__________ scan is horizontal on IP
Slow
Fast
What is the source is stimulating light for CR ??
The laser
X-rays interact with _____ and form the latent image by exciting electrons into a higher metastable state.
SPS
What is a collection element ?
May be a photodiode, ccd, or thin film transistor (TFT)
How much percentage is fill factor ??
80%
In direct DR, no scintillation phosphor is involved.
True or false
True
What is both the capture element and coupling element in DR ??
A-Se
Amorphous selenium
What does a thin film transistor do??
What is a charge coupling device ?
Collect electrons
Light sensitive pixel element
