Equipment Operation and Maintenance

Grid-controlled tube Designed to turn on and off rapidly, providing short precise exposures Use in fluoro and in capacitor discharged (condenser-discharge) mobile units Uses a molybdenum focusing cup

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 view  magnification 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 #9,24,30,36,38,40,44,47,54 63, 69,70

AEC

Collimation and AEC Photodiode –light sensitive –under table, behind cassette ion chamber –charge sensitive –above bucky and cassette –#10,14,25,27,34,81,92,102,113,

CIRCUITS

Self induction = autotransformer and choke coil Mutual induction =High voltage transformer & filament circuit V = V S = N S V P = N P I = N S = I P N P= I S

Rectifiers Filament circuit rheostat filament circuit

Motor and generators Rheostat Star and wye configurations –transformer windings in 3-phase circuits –5,20,23,26,35,45,46,51,52,53,74,77

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 35,64,96,97,99,105, 106

Tomography Thinner the cut the _________the angle 43

QUALITY CONTROL TESTS SPINNING TOPTIMER WIRE MESH SCREEN/FILM CONTACT PENETROMETERKVP AND CONTRAST STAR PATTERNFOCAL SPOT SIZE CUTIE PIE ROENTGEN DOSIMETER WISCONSIN TEST TOOL KVP IN BEAM GEIGERRADIOACTIVITY

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 #18,28,41,50,57,61,66,65,68,

TUBE LIFE/HEAT LOAD #6,12,16,33,44,73,77,101,

Mobile radiography, CT, Misc Capacitors- temporarily stores energy- no battery 2,3,4,22,37,42,55,58,71,78,87,88,120

DIGITAL Corectec

Misc. Light absorbing dye in screens reduce diffusion of fluorescent light