External Structures Flashcards
External Structures
➢ support structure,
➢ protective housing,
➢ glass or metal enclosure.
is probably the most frequently used. It consists of two perpendicular sets of ceiling-mounted rails. This allows for both longitudinal and transverse travel of the x-ray tube.
Ceiling support system
When the x-ray tube is centered above the examination table at the standard SID, the x-ray tube is in a
Preferred Detent position
➢has a single column with rollers at each end, one attached to a ceiling_x0002_mounted rail and the other attached to a floor-mounted rail.
Floor-to-Ceiling Support System
Interventional radiology suites often are equipped with C-arm support systems, so called because the system is shaped like a C.
C-Arm Support System
➢ made of lead and steel
➢ When x-rays are produced, they are emitted isotropically
➢Equal intensity in all directions.
Protective Housing
x-rays emitted through the window are called the
Useful beam or primary radiation
is thin and through which the useful beam of x-rays is emitted. Such a window allows maximum emission of x-rays with minimum absorption.
Window
X-rays that escape through the protective housing, they contribute nothing in the way of diagnostic information and result in unnecessary exposure of the patient and the radiologic technologist.
Leakage radiation or secondary radiation
guards against excessive radiation exposure and electric shock.
Protective housing
Protective Housing Functions:
Mechanical Support
An insulator
Thermal Cushion
Contains the X-Ray tube and its components
Glass or Metal Enclosure
is made of Pyrex glass to enable it to withstand the tremendous heat generated. The disadvantages are more likely to fail and lesser tube life.
Glass Enclosure
maintain a constant electric potential between the electrons of the tube current and the enclosure. Advantages are less likely to fail and longer tube life.
Metal Enclosure
2 SID
48 inches
72 inches
