Lesson 2 - Image Intensifier

what are the 2 different ways to capture image in digital fluoroscopy

using an image intensifier and flat panel detectors

what is the step by step process in digital fluoro using II

xray > patient and grid > II > CCD > output analog signal > ADC > digital data > computer > DAC > image

what is the purpose of II

the amplify the brightness of the image

what does II do

recieves xray beam and converts it into visible light

what does the envelope do and made out of

glass/metal and maintains a vacuum and provides structural support

image intensifier

what is the vacuum window

apart of the enevelope and is a thin layer of AI which forms a vacuum

what is the support layer

it supports the phosphor and photocathode, 1st part of the electrostatic lens, curved to focus the image

what is the input phosphor

converts xrays to light

what is teh photocathode

cb-sb that recieves light and turns it into electrons

what is made of cesium iodide?

input phosphor

what kind of curvature does the input phosphor have

concave

what the cesium iodide do in the input phosphor

increases conversion efficiency

what does the photocathode protect?

cesium iodide

where does the light produced by the cesium iodide hit

the photocathode

what is it called when you emit electrons

photoemission

what is photoemission

electrons are emitted form the photocathode after it is stimulated by light

what is the electrostatic focusing lenses

charged electrodes inside the glass enevlope. it accelerates the electrons focusing them toa. stream

what is the potential difference between photocathode and anode

25 000kV

what is the output phosphor made out of

zinc cadmium sulfide

what does the zinc cadmium sulfide do?

convert electrons into light