physics 2. ch 23. digital/ midterm

Question 1

two types of digital ?

Answer 1

CR and DR

Question 2

converts X rays (photons) to visible light

Answer 2

scintillator

Question 3

converts light photons into electrons. used in direct DR

Answer 3

photodetector

Question 4

does direct DR use a scintillator

Answer 4

no

Question 5

uses only a photodetector and TFT

Answer 5

Direct

Question 6

a rigid sheet with several layers designed to record and enhance transmission of the image from an X Ray beam

Answer 6

PSP

Question 7

contains the standard contrast, speed and latitude for an exam

Answer 7

LUT. look up table

Question 8

where are DELs found

Answer 8

in the TFT

Question 9

true or false?

CR systems are INDIRECT radiography with INDIRECT acquisition

Answer 9

true

Question 10

flat panel detectors are both ______ and ______

Answer 10

indirect and direct. both use TFTs

Question 11

A series of boxes laid out in the rows and columns that gives form to an image

Answer 11

matrix

Question 12

what determines the FOV field of view?

Answer 12

size of the detector

Question 13

what determines the number of shades of gray?

Answer 13

bit depth

Question 14

what is the digital standard for imaging

Answer 14

DICOM

Question 15

why is DR indirect considered a two step process.

Answer 15

X rays are converted to light first. then an electronic signal is created

Question 16

DR direct system has better resolution. why?

Answer 16

there are fewer conversion steps. X-rays go straight to an electronic signal with no light conversion in direct systems

Question 17

an electronic signal collector of electrical charges

Answer 17

TFT

Question 18

in what type of system is a high-voltage charge applied to the top surface of the selenium layer

Answer 18

DIRECT DR

Question 19

where would you find cesium iodide?

Answer 19

scintillator

Question 20

a photo diode is a light collector. name one:

Answer 20

amorphous silicon

Question 21

direct DR uses a photoconductor instead of a photodiode. it doesn’t use light as a separate step like indirect. it’s called ______ ______

Answer 21

amorphous selenium