Imaging Equipment and Maintenance

Question 1

Is the most frequent used system. It consists of two sets of rails mounted to the ceiling directly over the radiographic table.

Answer 1

Ceiling support

Question 2

When x-ray tube is centered above the examination table at the standard SID, the x-ray tube is in a preferred _____ position.

Answer 2

Detent

Question 3

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 3

Floor ceiling support system

Question 4

Interventional radiology suites often are quipped with C shape arm

Answer 4

C arm support system

Question 5

guards against excessive radiation exposure and electric shock.

Answer 5

Protective housing

Question 6

how many leakage of radiation thus the protective housing reduce?

Answer 6

less than 100mR/hr at 1m

Question 7

30 to 50 cm long and 20 cm in diameter` size of x-ray tube
Pyrex glass to enable to withstand the tremendous heat generated.

Answer 7

GLASS/ METAL ENVELOPE OR ENCLOSURE

Question 8

what is the area of the tube window?

Answer 8

5cm^2

Question 9

what causes arcing and tube failure?

Answer 9

as the glass enclosure ages, some of the tungsten vaporizes to the walls of enclosure.

Question 10

Is the negative side of the x-ray tube

Answer 10

cathode

Question 11

what is the melting point of the tungsten?

Answer 11

3410 degree Celsius

Question 12

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

Answer 12

Filament

Question 13

what is the filament made out of?

Answer 13

thoriated tungsten

Question 14

what is the dimensions of the filament?

Answer 14

2mm in diameter, 1 or 2 cm long

Question 15

why does the thorium is added to the filament?

Answer 15

increases the efficiency of the thermionic emission and prolongs tube life

Question 16

an x-ray 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

The filament is embedded in a metal cup called the

Answer 17

Focusing Cup

Question 18

without focusing cup the electron beams are

Answer 18

spread beyond the anode

Question 19

with focusing cup the electron beams are

Answer 19

condensed and directed to the target

Question 20

what does it call when the xray tube have 2 focal spots?

Answer 20

dual spot

Question 21

is used when better spatial resolution is required. SFS range from 0.1 to 1mm

Answer 21

small focal spot

Question 22

is used when large body parts are imaged and when other techniques that produce high heat are required.
LFS range from 0.3 to 2mm

Answer 22

large focal spot

Question 23

the positive side of the xray tube

Answer 23

anode

Question 24

what are the two types of anode

Answer 24

stationary and rotating

Question 25

x-rays tubes are used in dental x-ray imaging system, some portable imaging system and other special purpose units in which high tube current and power are not required

Answer 25

stationary anode

Question 26

is a shaft-like structure made primarily of copper.

Answer 26

rotor

Question 27

attaches the rotating target area to the rotor.

Answer 27

stem

Question 28

is a circular, disk-like structure with a slanted or beveled edge. --It serves as the target for receiving electrons as they move from the cathode to anode.

Answer 28

target

Question 29

is the area of the anode struck by the electrons from the cathode.

Answer 29

target

Question 30

what are the reasons why tungsten is the element of choice in xray tube?

Answer 30

high atomic number (74) thermal conductivity (efficeint for dissipating heat) high melting point (3410)

Question 31

x-ray tube allows the electron beam to interact with as much larger target area.

Answer 31

rotating anode

Question 32

RPM of the rotating anode

Answer 32

3410- 10,000 RPM

Question 33

copper, because it is poor heat conductor.

Answer 33

STEM

Question 34

is used to turn the anode.

Answer 34

induction motor

Question 35

it is an agulation of the anode to increase the focal spot size but still remain the small effective focal spot size that can result to increase in recorded detail and better spatial resolution

Answer 35

line focus principle

Question 36

two focal spot is called

Answer 36

biangular target

Question 37

results in smaller effective focal spot and less radiation intensity on the anode side of the x-ray beam.

Answer 37

anode heel effect

Question 38

The _____ the anode angle, the _____ is the heel effect.

Answer 38

smaller, larger

Question 39

some of the electrons bounce off the focal spot and then land on the other areas of the target, causing x-rays to be produced from outside the focal spot.

Answer 39

extrafocal radiation