THE X-RAY UNIT THE BASICS

WHAT FOUR COMPONENTS ARE IN TYPICAL RADIOGRAPHIC ROOM? 1. X-RAY TUBE 2. OPERATING CONSOLE 3. HIGH VOLTAGE GENERATOR 4. X-RAY TABLE

THE X-RAY TUBE Chapter 6 in Bushong OVERHEAD Ceiling suspension Sets of rails-controls longitudinal/transverse positioning Telescoping column for controlling vertical distance. FLOOR Tube-support column mounted on floor Same positioning options as overhead Counter weight on back of telescoping column. Why?

OTHER COMPONENTS ON X-RAY TUBE Collimator light Collimator controls Transverse lock Horizontal lock Longitudinal lock Vertical lock Tube head lock Tape Measure

C-arm Protective housing Isotrophically Window Useful beam Leakage Acceptable level of leakage is….?

What is the typical voltage range? What is the typical current range? CHAPTER 5 What is the typical voltage range? What is the typical current range?

X-RAY TABLE Must be radiolucent Can be tilted Float Holds bucky Has weight limit of 300lbs(Carbon-fiber) Easily cleaned, hard to scratch and without crevices

X-RAY CONSOLE Allows the radiographer to control the x-ray tube current (mA) and the voltage (kVp) so that a useful image is produced. ? Controls the quantity ? Controls the quality What does a line voltage compensator do?

AN R/F ROOM Contains a radiographic unit Contains a fluoroscopic unit located under radiographic table used in studies where it is necessary to watch a procedure on a monitor using x-rays.

HIGH VOLTAGE GENERATOR Housed within the x-ray room

Mobile radiography

mAs AND THE IMAGE ON THE FILM Fauber pgs 51-53 What is mAs? mAs = the mA X exposure time mAs is the quantity of x-rays mAs produces the overall blackening(DENSITY) on the film or brightness on filmless image receptors Pg 53-note the relationship between density and brightness

kVp and the image produced on the film (pgs 53-57) What is kVp? Controls the quality or penetrating quality of the x-ray beam Produces the varying shades of gray on the film. (variations of brightness and density) Gray scale Long or low and short or high contrast

Anatomic part and contrast Range of densities Tissue composition Pgs 57-58

Intro to Digital Imaging Fauber and Carter Carter pgs 80-82 Does KVP matter anymore? Does mAs matter anymore?

Four radiographic qualities Density Contrast ------------------------ Spatial resolution Recorded detail Size/Shape distortion Overall blackness Difference between adjacent densities ----------------------- Smallest object detected (DR) Sharpness of the lines of an image Misrepresentation of the true size or shape of image

Controlling and influencing factors What might control or influence the four radiographic qualities? Density Contrast Recorded detail Distortion Images 4-28,4-29, 4-30, 4,31 pg 104 Fauber Images 5-11, 5-15, Figure 5-16, all images on pg 130-131 Fauber

Sharpness vs. Visibility Driving on a foggy night (visibility) Driving after having drops in your eyes (Sharpness)

Good images vs Bad images Over exposed Over penetrated Poor detail distortion