Test 7 x-ray tube

true

T/F the cathode is the negative side of the xray tube

false

T/F the filament is set in the cathode assembly outside of the focusing cup

false

T/F electrons in the thermionic cloud are driven from the cathode to the anode with 100%

true

T/F most xray tubes have dual focus arrangement

true

T/F to prolong xray tube life the exposure switch should be partially depressed for a few seconds before complete depression occurs

false

T/F filament saturation occurs when the negative charge of the electron cloud opposes the emission of additional electrons from the filament

true

T/F the faster the anode rotation the better the heat dissipation

false

T/F like the cathode the anode is comprised of a single metal called tungsten

false

T/F the line focus principle is used to reduce the actual area of the focal spot

true

T/F when the target is less than 45 degrees the effective focal spot is smaller than the actual focal spot

false

T/F as the anode target angle increases the primary bea, field size increases

true

T/F in radiology the term focal spot size refers to the effective focal spot

false

T/F according to the anode heel effect the radiation intensity is greater on the anode side

false

T/F the entire cathode and anode assemblies are enclosed within the glass envelope

true

T/F off focus radiation is of significantly lower energy is of significantly lower energy than the primary beam itself

2, 3 and 4

which of the three of the following imaging modalities use an x-ray tube

1. MRI

2. mammography

3. fluoroscopy

4. CT

anode

what component of the xray tube is the source of free electrons

anode

what component of the xray tube is the source of xrays

free electrons

the term space charge within the x-ray tube refers to

1000 mA

the space charge effect limits the functional milliamperage of the xray tube to approximately

abdominal imaging on a bariatric patient

what is the principal advantage of using the large filament within a dual focus xray tube

beam quantity across the xray field

the anode heel effect is defined as a varation in which of the following

lower intensity

as a result of the anode heel effect the anode side of the xray field demonstrates

increased focal spot and increased heat capacity

the use of an xray tube with a large anode results in which two of the following

x-ray absorption within the anode

what is the anode heel effect caused by

more uniform receptor exposure

directing the anode side of the x-ray field towards the toes during an anteroposterior projection of the foot results in which of the following

decreased focal spot size and decreased heat capacity

the use of an x-ray tube with a small anode angle results in which two of the following

decreased source to image distance

which of the following exposure modifications will increase the anode heel effect

30

how many bones are in the right upper extremity, excluding sesamoid

ulnar flexion

when doing a tangential projection of the PA wrist for the navicular, the wrist should be in

femur

the largest, strongest and heaviest bone in the body is

bursae

many joints are enclosed in a sac like cavity filled with vicid fluid what are these called

15-20 degrees

in order to best demonstrate the mortise, the ankle must be rotated medially

Lawerence

another name for a trans thoracic view of the upper humerus is called

difficulty swallowing

what does dysphagia mean

anterior

a y view shows a dislocation of the humeral head beneath the coracoid process this is a ___________ dislocation

suspension of breathing

what does apnea mean?

unknown origin

the term idiopathic means

speed of the anode

the temperature of the filament in modern xray equipment is directly related to the

the lesser trochanter

in AP shoulder internal rotation of the humerus demonstrates

attenuation

the reduction in xray photon intensity as it passes through a material is

45

an average diagnostic xray tube filament life is only about

burns and lukemia

protective or reverse isolation is required for compromised or immunocompromised patients include

20-30 degrees

when doing a lateral knee you need to see the joint space how much do you need to bend the knee

intercondylar fossa

the beclere method is used to demonstrate

greater trochanter

which process is located

epiphysis

bone formed from a secondary center of ossifcation, commonly found at the ends of long bones

ilium

which bone of the hip extends inferiorly from the acetabulum and joins with the inferior ramus of the pubic bone

glenoid cavity and humeral head

the shoulder girdle is formed by

anode, stator and rotor

anode assembly

210-220 volts

nearly all xray equipment operates at an incoming line of voltage of

electronic

most common type of timer is

medial oblique foot

sinus tarsi, cuboid and 5th tuberosity is seen best in a

ap lateral

what shows the radial head and neck free of superimposition

cuboid

what lies between the calcaneus and the 4th and 5th metatarsal

12 degrees

to cover a 14×17 inch field at 40 inches the minimum target angle required is

increases

as the kvp increases the percent of photon interactions by photoelectric

false

T/F when the target angle is less than 45 degrees the effective focal spot is larger than the actual focal spot

Lawrence

when trauma angle is less than 45 degrees the effective focal spot is larger than the actual focal spot

space charge effect

as more and more electrons build up in the area of the filament their negative charges begin to oppose the emission of additional electrons this phenomenon is called

3200-3600

common rotating anodes spin at

internal rotation

in which position of the shoulder is the greater tubercle seen superimposed on the humeral head

low and high

a high kvp results in a _________ contrast image while a low kvp results in a _________ greater contrast image

increase kvp by 15%

which produces the same effect as doubling the mAs

low voltage

autotransformer is on what side of the tube

off focus radiation striking the anode

which causes pitting of the xray tube target

protons and neutrons

in a neutral atom the electrical neutrality is achived by maintaining a balance

trachea

which does not pass through the diaphragm

airborne

TB

contact

VRE

droplet

flu

13%

what is the ripple of a three phase six pulse

effective focal spot

what term describes the area where the xray beam is projected towards the patient

severity of the heel effect

focal spot size

heat load capacity

anode heel effects

beam quantity across the xray field

the anode heel effect is defined as a variation in which of the following

lower intensity

as a result of the anode heel effect the anode side of the xray field demonstrates

increased focal spot size

increased heat capacity

to use the of an xray tube with a large anode angle results in which two of the following

xray absorption within the anode

what is the anode heel effect caused by

more uniform receptor exposure

directing the anode side of the xray field towards the toes during an anteroposterior projection of the foot results in which of the following

decreased focal spot and decreased capacity

the use of an xray tube with a small anode angle results in which of following

decreased source to image distance

which of the following exposure modification increase the anode heel effect

increased effective focal spot

which of the following is a potentially negative consequence of an increased anode angle

effective focal spot size decreases and heel effect increases

which of the following occurs when the anode heel angle decrease

actual focal spot

the source of xray emission within an xray tube is called

heat

electron interactions within the xray tube anode primarily create

effective focal spot

the area of the xray beam projected towards the patient is described as the

anode angle and effective focal spot size

the line focus principle describes the geometric relationship between which of the following factors within an xray tube

6 degrees

which of the following anode angles with the same size actual focal spot can create a radiographic image demonstrating the highest spatial resolution

22 degrees

which of the following anode angles with the same size actual focal spot can tolerate the highest technical setting without overheating

increased spatial resolution and decreased anode heat capacity

when comparing a small anode angle to a large anode angle a small anode angle with the same size focal spot will result in

decreased spatial resolution and increased anode heat capacity

utilizing an xray tube within a large anode angle compared to a tube with a small angle and the same size actual focal spot

7 degrees

a radiographer has a choice of multiple radiographic systems each using a different anode angle

2.4cm

a radiographer has the choice of multiple radiographic systems each using a different focal spot size

heat energy created in the xray tube

the term tube loading refers to which of the following

99%

what percent of the electron energy is converted to heat at the anode during xray production

kvp x mA x time x waveform

what is the formula for total heat units created

anode rotation speed

filament material

exposure time

what are the three factors that influence heat capacity

filament size

techs can reduce the chance of excessive heat production and xray tube damage by

mammo

fluoro

CT

which three following imaging modalities use an xray tube

anode

what component of the xray is the source of free electrons