fluoroscopy 2

100問 • 1年前

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The resolution of the fluoroscopic image is directly affected by the WHAT?. Many video monitoring systems are limited to a 525-line raster pattern where fluoroscopic geometric factors affect the overall resolution of the image.

video monitoring system

Many video monitoring systems are limited to a WHAT? where fluoroscopic geometric factors affect the overall resolution of the image.

525-line raster pattern

Many video monitoring systems are limited to a 525-line raster pattern where WHAT? affect the overall resolution of the image.

fluoroscopic geometric Factors

Many video monitoring systems are limited to a 525-line raster pattern where fluoroscopic geometric factors affect the

overall resolution of the image.

It is affected by the same factors as in static radiography

contrast

It is directly affected by the video monitoring system

resolution

The fluoroscopic geometric factors include

Mi FITFOV minification flux gain focal point input and output phosphor diameter thickness viewing system resolution oid

Affected by same parameters as static radiography

size distortion

Size distortion is affected by

same parameters as static radiography

Primarily afftects the size distortion

oid

Geometric problems in what?

shape of input screen

shape helps reduce shape distortion, but does not remove it all

concave shape

Concave shape helps reduce what?

shape distortion

Vignetting or pin cushion effect

shape distortion

the presence of a brighter light intensity at the center of the fluoroscopic image on an image intensifier than at the periphery of the field.

vignetting or pin cushion effect

Blotchy, grainy appearance

quantum mottle

Quantum mottle appearance

Blotchy, grainy appearance

Quantum mottle is caused by

too little exposure

Remedial for quantum mottle

increase mA

is the grainy appearance which is caused by insufficient radiation to produce a uniform image.

quantum mottle

Quantum mottle is the grainy appearance which is caused by WHAT? To produce a uniform image.

insufficient radiation

Quantum mottle is controlled by

mA and time

It is controlled by the mA and time

quantum mottle

assist in reducing quantum mottle.

increasing the efficiency of any of the factors

Viewing system

video viewing system video camera tubes video camera CCD video monitor digital

Video camera tubes

cathode anode

Video camera coupled to output screen and monitor

closed circuit television

Vidicon or Plumbicon tube

video camera

Video cameras

Vidicon or Plumbicon tube ccd

plumbicon or vidicon tube difference

target materials plumbicon has faster response time

The standard types video camera are called

vidicon plumbicon ccd

Video camera tubes are similar in operation

vidicon plumbicon

The video camera tubes have WHAT which maintains a vacuum and provides support for the internal components.

glass envelope

The video camera tubes have a glass envelope which what?

maintains a vacuum and provides support for the internal components.

Inside the TV camera tube are what?

cathode electron gun, electrostatic or focusing coils, and the target assembly that is also the anode.

is a video camera tube design in which the target material is a photoconductor.

vidicon tube

Vidicon tube is a video camera tube design in which the target material is a what?

photoconductor.

a storage-type camera tub

vidicon tube

The vidicon is a storage-type camera tube in which WHAT? is formed by the imaged scene radiation on a photoconductive surface which is then scanned by a beam of low-velocity electrons.

charge-density pattern

The vidicon is a storage-type camera tube in which a charge-density pattern is formed by the on WHAT? a photoconductive surface which is then scanned by a beam of low-velocity electrons.

imaged scene radiation

The vidicon is a storage-type camera tube in which a charge-density pattern is formed by the imaged scene radiation on a photoconductive surface which is then scanned by what?

beam of low-velocity electrons.

Used frequently in broadcast camera applications

plumbicon

these tubes have low output, but a high signal-to-noise ratio.

plumbicon tube

Video camera tubes components

cathode electromagnetic focusing coils electrostatic deflecting coils anode

Shapes electron beam

control grid

Cathode assembly

heating assembly control grid

Cathode heating assembly

electron gun thermionic emission

Electron gun and thermionic emission is found in

heating assembly

Some fluoroscopy systems use a this instead of a video tube

CCD

a semiconducting device capable of storing a charge from light photons striking a photosensitive surface.

ccd

stores these electrons which make up the latent image.

CCD

The ccd stores these electrons which make up what

latent image

A video signal is then emitted in a what? by discharging the stored electrons as pulses.

raster scanning pattern

A video signal is then emitted in a raster scanning pattern by

discharging the stored electrons as pulses.

The main advantage of the CCD is the extremely fast discharge time which is useful in WHAT where high-speed imaging is critical to visualizing blood flow.

cardiac catheterization

The main advantage of the CCD is the extremely fast discharge time which is useful in cardiac catheterization where high-speed imaging is critical to what?

visualizing blood flow.

The CCD operates

lower voltage

it is more sensitive than video tubes,

ccd

When ccd operated at low voltage it makes the ccd what?

prolonged its life

the type of monitor used to display the fluoroscopic image

cathode ray tube

CRT is like

a video tube

Crt Like a video tube, it consists of a

vacuum tube, an electron gun (cathode) with focusing and deflecting electromagnets for steering the electron beam.

Like a video tube, it consists of a vacuum tube, an electron gun (cathode) with focusing and deflecting electromagnets for what?

steering the electron beam

It is much larger than the video tube and has an anode assembly with a fluorescent phosphor coated on the inside of the front screen.

crt

It is much larger than the video tube and has an anode assembly with a what? on the inside of the front screen.

fluorescent phosphor coated

Anode assembly in crt

face plate single plate target

Positively charged thin film of graphite

signal plate

Signal plate is what

Positively charged thin film of graphite

Changes light pattern to electronic signal sent to video system

target

Target function

Changes light pattern to electronic signal sent to video system

Thin insulating mica minerals

target

Thin insulating mica minerals are what

group of sheet silicate or phyllosilicate

Matrix of globules of photoconductive material

target

Target assembly

thin insulating mica minerals matrix of globules of photo conductive minerals

Target of vidicon

antimony trisulfide

Target of plumbicon

lead oxide

Semiconducting device

video camera ccd

Video camera ccd emits electron in what?

in proportion to amount of light striking photoelectric cathode

Fast discharge eliminates lag

video camera ccd

Emits electrons in proportion to amount of light striking photoelectric cathode

video camera ccd

Operate at lower voltages than video tubes

video camera ccd

More durable than video tubes

video camera ccd

Image intensifier output screen coupled to TFTs

digital fluoroscopy

Image intensifier output screen coupled to what?

tft

In digital fluoroscopy it is coupled to TFTs

image intensifier output screen

These are connected to each pixel element

tft photodiode

limited in favor of radiation exposure concerns

resolution

Resolution limited in favor of radiation exposure concerns

digital fluoroscopy

Resolution limited in

favor of radiation exposure concerns

Recording the Fluoroscopic Image

Dynamic systems Cine film systems Videotape recording Static spot filming systems

Film used in recording the fluoroscopic image

105 chip film

Dynamic system

cine film videotape

Movie camera intercepts image

cine film system

Cine film formats

16 mm and 35 mm

Record series of static exposures at high speed

cine film system

Record series of static exposures at what

high speed

Record what? at high speed

series of static exposure

Cine film frame

30-60 frames per second

Offer increased resolution

cine film system

100

Cost of increase resolution in cine system

increase patient dose

M#5 Section and Title v2

ユーザ名非公開 · 32問 · 13日前

M#5 Section and Title v2