Fluoroscopy

fluoroscopy

specialized radiographic equipment used to visualize the motion of internal structures and fluids is?

a dynamic moving image

fluoro will produce?

static

plain radiography is referred to as?

Thomas Edison in 1896

the first fluoroscope was invented by?

a c-arm

a fluoroscopic x-ray and image receptor is mounted to?

-under table unit

-over table unit

what are the two types of fluoroscopy machines?

the carriage

what is the arm called that supports the equipment over the table is called?

control panel

power drive, shutters, image selection =

older machines (like a cassette)

spot imaging is seen in?

a deadmans switch

the foot exposure switch is what type?

over the table

which fluoro type has a higher dose?

true

T/F the carriage must be engaged for fluoro to work?

longer

fluoroscopic x-ray tubes are designed to operate for _______ periods of time at a much lower mA

50-1200 mA

a diagnostic tube operates at?

.5-5 mA

fluoroscopy operates at?

SOD

patient dose is increased in fluoro die to the decreased?

700 mR

UGI approx =

1300 mR

BE approx =

body part

kVp is dependent on the _____________ being examined

high (90-120 kVp)

barium studies use a ______ kVp

low (60-80 kVp)

iodine studies use a ______ kVp

-conventional

-digital conversion (most common today)

what are the 2 types if fluoro technology?

conventional fluoroscopy

in the old days radiologists looked directly at the fluoroscopic screen either held in his/her hands or attached to the primary beam

1948

when were image intensification tubes were developed?

image intensification tubes

the image goes to a TV monitor, spot film device, or cine camera which replaced the mirror system

conventional fluoro

uses an x-ray tube, image intensifier and a television system to produce an analog image

105 mm film

photospot camera =

1000-6000

image intensification utilized the radiation that passes through the patient and enhances the image by electronically making the image ______________ times brighter than the old fluoroscopy

high

for detail to be visible the image brightness must be?

image brightness

image intensifiers were created with the principles advantage being increased?

lumen per square meter or lux

units of illumination is measured in units of?

100-1000 lux

radiographs are visualized under illumination levels of?

dark adapted

before image intensifiers the radiologists had to become ____________ by standing in a totally dark room or wearing red goggles

fluoroscopic screens

-much like x-ray screens

-converts x-rays to light

-phosphor used: zinc cadmium sulfide

zinc cadmium sulfide

fluoroscopic screens phosphors are made of?

image intensifier

tube receives the remnant x-ray beam, converts it into light and increases the light intensity =

input phosphor

the image intensifier x-rays pass through the glass envelope and hit the?

cesium iodide

the input phosphor is made out of?

visible light

the input phosphor converts x-rays to?

photocathode

the input phosphor converts x-rays to visible light which strikes the?

cesium and antimony

the photocathode is a thin metal layer made up of?

photocathode

what absorbs the light energy received from input phosphor and emits electrons?

intensity of the light reaching it

the number of electrons emitted is directly proportional to the

about 25,000 volts

what is the potential difference between the photocathode and the anode?

anode

electrons will be accelerated toward the?

electrons

electrostatic focusing lenses focus the?

-x-ray beam

-input phosphor

-photocathode

-focusing lenses

-hole of anode

-output phosphor

-monitoring system

what is the order of the image intensifier?

light is produced

once electrons strike the output phosphor what happens?

zinc cadmium sulfide crystals

the output phosphor is made out of?

monitoring system

the light is directed to a?

photocathode to the electron beam, electrons to the output screen, output to the human eye

x-ray beam to the input screen, input to the photocathode =

electrons into another light image

x-rays transform into light, back into

equivalent to one another

-1 keV x-ray photon

-1000 light photons

-50 photoelectrons

-3000 light photons

50-75

each photoelectron that hits the output phosphor produces _________ times as many light photons

flux gain

gain in brightness achieved by the II is a result of the electron acceleration and image magnification =

50

a typical II has a flux gain of about?

flux gain

ratio of the number of light photons at the output phosphor to the number of x-rays at the input phosphor

# of light photons output /

# of x-ray photons input

what is the formula for flux gain?

magnification gain

the increase in brightness caused by electrons being focused into a small area =

input diameter /

output diameter and square the answer

what is the formula for magnification gain?

magnification x flux gain

what is the formula for brightness gain?

5,000 to 30,000

the brightness gain of most II’s is?

6” (15cm) to 12” (30cm) in diameter

input phosphors range from?

1”(2.5 cm)

a typical output phosphor had a diameter of?

multi field

most II’s are what type?

examples of multi field

-dual focus

-dual field

-tri focus

-tri field image intensification

dual focus

9”/6” (23cm/15cm) or 10”/7” (25cm/17cm) =

tri focus

10/7/5” (25/17/12cm) or 9/6/4.5” (23/15/10 cm) =

9”

on a 9/6 II the maximum diameter of the input phosphor is?

magnification

the electron focal point is moved further from the output phosphor causing?

increase

mag mode will __________ magnification

resolution

mag mode increases?

less brightness

minification gain is reduced =

needs an increase

when using mag mode what needs to be done to the mA?

false

T/F mag mode decreases patient dose?

vignetting

the loss of brightness at the periphery is called?

automatic brightness control (ABC) or automatic brightness stabilization (ABS)

maintains the brightness of the image by automatically adjusting the exposure factors (mA and kVp) according to the density and contrast of the subject

-flat panel

-charged couple device (CCD)

what types of digital fluoroscopy is used today?

no cassette is required

what advantage does digital have over conventional fluoroscopy?

charge coupled device (CCD)

in digital fluoro the image intensifier output screen image is coupled via a?

analog to digital converter

a CCD converts visible light to an electrical charge that is then sent to the?

cardiac catheterizations

a CCD’s rapid discharge time virtually eliminates image lag and is particularly useful in high speed imaging procedures such as?

CCD

-still uses a II

-a layer of crystalline silicon which illuminates and creates an electrical charge

-these charges are then sorted, pixel by pixel to make the digital image

output phosphor

the CCD is mounted o0n the _______________ of the II

-smaller and lighter than the II and CCD for easier manipulation

-composed of cesium iodide

-distortion free

optical mirror system

-field of view is small

-only one person can use it at a time

cinefluoroscopy or cinecamera

-a movie camera records the images on film

-used in cardiac catheterization

-patient dose is very high

-image quality is high

35mm

16mm or 35mm are used which has a higher quality and higher dose?

framing frequencies

7.5, 15, 30, 60 and 90 =

35mm wide and 400ft

the cine camera film is smaller (_________) and longer (_____) on a roll the camera is capable of operating at 90 images per second

increase in patient dose

increased framing frequency =

30 frames per sec.

what is the usual framing frequency?

the film is in position for exposure

the tube is emitting x-rays only when?

spot film

___________- uses essentially the same technology as conventional screen film radiography

away from the II

when fluoro is on the cassette is positioned?

3-5 and 200-400

when spot filming the cassette is put into position and the tube changes from low mA (______) to high mA (_______)

true

T/F spot films produce high patient dose

the delay involved in moving the cassette into position for the exposure

what is a disadvantage of spot films?

photospot camera

spot film is also called?

spot film camera

receives image from the output phosphor so less patient dose than cassette spot film about half the dose =