RAD 150 Fluoroscopy Fluoro’s primary function is to enable one to view the patient in “real time” with dynamic (motion)

Fluoro was first invented by Thomas Edison in 1896 Utilized a conventional x-ray unit with a fluorescent screen that would convert the x-rays exiting the patient to low level light the radiologist could view

Image Intensified Fluoro

II Fluoro Increased image brightness with II over direct fluoro is the biggest advantage of II Usually controlled by “automatic brightness control” (ABC) that the radiologist can preset and control

Eyes use rods and cones Photopic vision – daylight vision uses the CONES Scotopic vision - night time vision and uses the RODS

Fluoro Techniques Fluoro usually is operated at 5 mAs and uses highest optimum kVp Protective Fluoro measures Bucky slot cover Lead curtain 5 min back up timer Lead gloves and aprons (secondary barriers!) Distance

Image intensifier tube Dang it – I couldn’t find a diagram to import here!!!!!!! Input phosphor Photocathode (photo emission) Evacuated glass envelope Electrostatic focusing lens (neg. charged!!!!) Anode Output phosphor

Gain Minification gain – ratio of input to output sizes Flux gain – ratio of # of input PHOTONS to output LIGHT PHOTONS Brightness gain (total brightness gain)= minification gain X flux gain

Fluoro Magnification Most fluoro II units have dual input phosphor sizes (9” and 6” [27/17 cm] Some have TRI – input (trifield tubes 27/17/12 cm) The crossover of the electron stream distance from the output phosphor determines the amount of magnification Mag mode = better spatial resolution, better contrast resolution, HIGHER pt. dose

TV Monitoring Must “couple” the output phosphor to a TV camera tube Vidicon tube is MOST frequently used – plumbicon also can be used Fiber optics and beam splitters are used to help direct the digitized image to the various destinations (TV monitor, photo spot film camera, VCR/CD recorder, cine camera)