1. RAD 350 Chapt. 25 Fluoroscopy Fluoro’s primary function is to enable one to view the patient in “real time” with dynamic motion Invented by Thomas Edison in 1896 – Utilized a conventional x-ray unit with a fluorescent screen that would convert the x-rays (remnant beam) to low level light the radiologist could view

2. Image Intensified Fluoro

3. 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 control)

4. Image Intensifier Dang it – I couldn’t find a picture, so draw the dang thing! – Input phosphore – Photocathode (photo emission) – Evacuated glass envelope – Electrostatic focusing lens (neg. charge) – Anode – Output phosphor

5. Image intensifier (I lied – here is the picture)

6. 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

7. 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’s distance from the output phosphor determines the amount of magnification Mag mode = better spatial resolution, better contrast resolution and HIGHER PT. DOSE!!!

8. TV/Monitor Viewing Must “couple” the output phosphor to a TV camera tube or CCD/TFT – Vidicon tube is the MOST frequently used tube Image orthocon and plumbicon are also used

9. Other viewing/imaging devices Fiber optics and beam splitters are used to help direct the digitized image to the various destinations (TV monitor, photospot film camera, VCR/DVD recorder, cine camera)

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

11. Conventional Fluoro Techniques (not digital fluoro) Fluoro usually is operated at 5 mA and uses the highest OPTIMUM kVp Protective Fluoro Measures – Bucky slot cover – Lead curtain – 5 min. back up timer – Lead gloves and aprons (5mm pb) – secondary barriers – Distance