The X-ray Tube

Question 1

it is the most frequent used system

Answer 1

ceiling support

Question 2

it consists of two sets of rails mounted to the ceiling directly over the radiographic table

Answer 2

ceiling support

Question 3

external structure has 3 components:

Answer 3

support structure
protective housing
glass or metal envelope

Question 4

internal structure has 2 components:

Answer 4

anode
cathode

Question 5

the rails are mounted perpendicular to each other so that the tube can move longitudinally along the length of the table and transversely in a perpendicular direction to the length of the table

Answer 5

ceiling support

Question 6

it has a single column with rollers at each end, one attached to a ceiling mounted rail and other attached to a floor mounted rail

Answer 6

floor ceiling support system

Question 7

interventional radiology suits often are equipped with _____

Answer 7

c arm support system

Question 8

it guards against excessive radiation exposure and electric schock

Answer 8

protective housing

Question 9

what are those xrays emitted through the window called?

Answer 9

useful beam

Question 10

the protective housing contains ___ that serves as both an insulator against electric shock and as a thermal cushion to dissipate heat

Answer 10

oil

Question 11

size of xray tube

Answer 11

30-50 cm long
20 cm in diameter

Question 12

it is a glass that enable to withstand the tremendous heat generated

Answer 12

pyrex glass

Question 13

it is the negative side of the xray tube

Answer 13

cathode

Question 14

it is a coil of wire similar to that in a kitchen toaster, except much smaller

Answer 14

filament

Question 15

filament is made of thoriated ____

Answer 15

tungsten

Question 16

it is when an xray tube filament emits electrons when it is heated, when the current through the filament is sufficiently high, the outer electrons of the filament atoms are boiled off and ejected from the filament

Answer 16

thermionic emission

Question 17

most diagnostic xray tube has two focal spots, one large and one small

Answer 17

dual focus

Question 18

it is a focal spot that used when better spatial resolution is required that has sfs range from 0.1 to 1mm

Answer 18

small focal spot

Question 19

it is a focal spot that is used when large body parts are imaged and when other techniques that provide high heat are required and has lfs range from 0.3 to 2mm

Answer 19

large focal spot

Question 20

two types of anode

Answer 20

stationary anode
rotating anode

Question 21

it is xray tubes that are used in dental xray imaging system, some portable imaging system and other special purpose units in which high tube current and power are not required

Answer 21

stationary anode

Question 22

it is a shaft like structure made primarily of a copper and it is a rotating device

Answer 22

rotor

Question 23

it attaches the rotating target area to the rotor

Answer 23

stem

Question 24

it is a circular, disk like structure with a slanted or beveled edge

Answer 24

target

Question 25

it serves as a target for receiving electrons as they move from cathode to anode

Answer 25

target

Question 26

anode is the positive side, it conducts ______ and radiates ____ and contains the target

Answer 26

anode is the positive side, it conducts electricity and radiates heat and contains the target

Question 27

target is made up of _____

Answer 27

tungsten

Question 28

it is an anode that allows the electron beam to interact with as much larger area

Answer 28

rotating anode

Question 29

stem is made up of _____ because it is poor heat conductor

Answer 29

copper

Question 30

it is an electromagnetic induction motor that is used to turn the anode

Answer 30

induction motor

Question 31

it results in an effective focal spot size much less than the actual focal spot size

Answer 31

line focus principle

Question 32

by angling the target, one makes the effective area of the target much special than the actual area of electron interaction

Answer 32

line focus principle

Question 33

it is an area that receives beam of electrons from cathode

Answer 33

focal spot

Question 34

actual xray sources

Answer 34

focal spot

Question 35

focal spot when the target angle is made smaller, the effective focal spot size is _____

Answer 35

focal spot when the target angle is made smaller, the effective focal spot size is also smaller

Question 36

two focal spot called

Answer 36

biangular target

Question 37

it is projected on to the patient with the size of the actual focal spot

Answer 37

effective focal spot

Question 38

it results in smaller effective focal spot and less radiation intensity on the anode side of the xray beam

Answer 38

anode heel effect

Question 39

low intensity anode, high intensity cathode

Answer 39

anode heel effect

Question 40

anode heel effect the smaller the anode angle, the ___ is the heel effect

Answer 40

anode heel effect the smaller the anode angle, the larger is the heel effect

Question 40

anode heel effect the smaller the anode angle, the ___ is the heel effect

Answer 40

anode heel effect the smaller the anode angle, the larger is the heel effect

Question 41

positioning the cathode side of the xray tube over the thicker part of the anatomy provides more uniform optical density on the film

Answer 41

anode heel effect

Question 42

it is when some of the electrons bounce off the focal spot and then land on the other areas of the target causing xrays to be produced from outside the focal spot

Answer 42

extrafocal radiation

Question 43

extrafocal radiation also called ___

Answer 43

extrafocal radiation also called off focus radiation

Question 44

it is undesirable, can extend the size of focal spot and can increase patient dose and reduces image contrast

Answer 44

extrafocal radiation

Question 44

it is undesirable, can extend the size of focal spot and can increase patient dose and reduces image contrast

Answer 44

extrafocal radiation