Crosswords week 2 ( digital fluoro) Flashcards
Period of time required for digital x-ray tube to switch on
Interrogation
Type of dose rate measured in rads/hour
Absobed dose
_____ progressive technology allows digital fluoro to keep pt. dose down
pulsed
Period of time digital x-ray tube is energized
Duty cycle
A computer reads information in ___ code
binary
Common digital subtraction technique rendering anatomy opaque while highlighting vessels is known as ___?
road mappng
Known to be a factor of one
quality factor
barrier thickness is measured in mm of ____
Lead
Rows & columns of pixels
Matrix
SI unit for rem
Sievert
Flat panel detector degrade with age, true or false?
false
HVL is measured in mm of ____?
Aluminum
Half value layer measures the ____ of the x-ray bem
Quality
5 rem is the occupational dose limit of exposure for an individuals ______?
body
Smallest element of digital image
pixel
ADC turns electronic signal into _____ signal
digital
Dose measured over a period of time
dose rate
CCD turns ___ signal into electronic signal?
light
Digital fluoro uses mA ___- than 100
greater
Measurement of occupational dose limits
rem
SI unit for rad
gray
The higher the SNR the ____ the image noise
lower
15 rem is the occupational dose limit of exposure for an individuals _____?
eye
Image quality is improved as pixel size ____
decreases
Measurement of absorbed dose
Rad
Most I.I’s are of multi-field because ___?
They provide more flexabilty in all fluoro exams
minification gain formula
(Input screen diameter )2 (over output screen diameter ) 2
Describe the size of the image that arrives at the OP from the IP?
undistorted image in minified form
What are the 2 methods of TV camera tube coupling?
Fiber optic cable & lens coupling
When the multifocus image intensifier is operated in the magnification mode, where is the focal point relative to when the intensifier is in normal mode?
The focal point is closer to the input phosphor (IP) in mag mode
The emission of electrons from an illuminated surface
Photoelectric emission
1/10th of the value layer is needed during ____
HVL
___ characterizes the quality of the beam
HVL
Why is video viewing of the fluoroscopic image advantageous
The image is brighter
TV monitoring allows for the storing ___ on ___ or____ for future playback.
image on disks or tapes
Term for the misrepresentation of object size and shape on a radiograph
distortion
Occupational dose for radiation worker is ?
5 rem / year
or 5000 mRem/ year
Spatial resolution is measured in _____/
line pair per mm
What are disadvantages of mirror optical systems
it is a one viewer system, significant amount of light loss from output phosphor
True or false: Differential absorption increases when kVp decreases to obtain short scale images. This results in higher pt. dose
True
