Equipment Operation and Maintenance
FLUOROSCOPY
INPUT PHOSPHOR
LARGE DIAMETER
CESIUM IODIDE
X-RAYS LIGHT
PHOTOCATHODE
LIGHT ELECTRONS
OUTPUT PHOSPOR
SMALLER DIAMETER
ELECTRONS LIGHT
FLUORO CONT.
FOCUSSING LENSES
VIDICOM/PLUMBICON
BEAM SPLITTING DEVICE
mA
ABS
AGC or ABC
FLUX GAIN=# OF OUTPUT LIGHT PHOTONS
# OF INPUT LIGHT PHOTONS
MINIFICATION GAIN
= Diameter of input (squared)
diameter of output (squared
BRIGHTNESS GAIN:
minification x flux
Trifield Tubes
25/17/12 smaller diameter of input phosphor reduces:
field of viewmagnification
minification gain dimmer image
Larger film format greater the # of films =higher patient exposure
Cinefluoroscopy
rapidly obtained photospot image (35mm film)15,30,60,90 frames per sec.
cardiac cath
Spot film
12 frames per sec
smaller film size
cassette loaded
FLUORO QUESTIONS
#1,13,19,30,38,39,47,54,69,75,89
100, 114
AEC
Collimation and AEC
Photodiode
light sensitive
under table, behind cassette
ion chamber
charge sensitive
above bucky and cassette
#10,16,27,34,81,92,102,113,116
CIRCUITS
Self induction = autotransformer and choke coil
Mutual induction =High voltage transformer & filament circuit
V = VS = NS
VP= NP
I = NS = IP
NP=IS
Rectifiers
Filament circuit
rheostat
filament circuit
Motor and generators
rheostat
parallel circuits
series circuits
Star and wye configurations
transformer windings in 3-phase circuits
20,23,26,31,37,45 ,51,52,53,74,78
THREE PHASE/SINGLE PHASE
HU
single phase=ma x time x kvp
three phase/ 6 pulse
ma x time x kvp x 1.35
three phase/12 pulse
ma x time x kvp x 1.41
VOLTAGE RIPPLE
Single phase
three phase 6 pulse
three phase 12 pulse
100%
13%
4 or 3%
?’s 35,64,88, 84,85,96,97
Tomography
Thinner the cut the _________the angle
2, 40, 43
QUALITY CONTROL TESTS
SPINNING TOP TIMER
WIRE MESH SCREEN/FILM CONTACT
PENETROMETER KVP AND CONTRAST
STAR PATTERN FOCAL SPOT SIZE
CUTIE PIE ROENTGEN DOSIMETER
WISCONSIN TEST TOOL KVP IN BEAM
GEIGER RADIOACTIVITY
spinning top tests
Spinning top tests
half wave/single phase = exposure time x 60
Full wave/single phase = exposure time x 120
Three phase –exposure time =arc size/360
timers and rectifiers
dots and dashes(12 dots of 1/10sec, 24 dots of 1/5 sec, 6 dots for 1/20 sec)
synchronous spinning top
solid arc
#5,28,29,50,57,61,70,
TUBE LIFE/HEAT LOAD
#6,7,44,,73,99,104,
Mobile radiography
Capacitors- temporarily stores energy-no battery
4,42,62,87
DIGITAL
#3,9,16,56,67
Misc.
Light absorbing dye in screens reduce diffusion of fluorescent light