Deck 6: Medical Imaging

Question 1

The technical factor having the most affect on radiographic density is:

A) mAs
B) kVp
C) distance
D) grid ratio
E) all may have a great impact on density

Answer 1

E
While mAs is typical modulated to change radiographic density,several factors have an equal or greater affect on density.KVp,distance,grid ratio,and other factors can have a tremendous affect on the image density.

Question 2

Components of a modern x-ray tube include:

A) cathode filament
B) rotating anode
C) glass envelope
D) all of the above

Answer 2

D
A typical x-ray tube includes all of those components listed above.Other components include the protective housing and focusing cup.

Question 3

Thermionic emission is the process by which electrons are liberated from the positively charged anode.

Answer 3

False
Through the process of thermionic emission,electrons are released from the negatively charged cathode.This process is called thermionic as the electrons,ions,are liberated in response to heat,thermal energy.

Question 4

Beam quality is affected by changes in:

A) kVp
B) potential difference in the x-ray tube
C) voltage
D) all of the above

Question 5

Additive pathologies affect tissue density such that the affected anatomy may appear _________ on the radiograph.

A) lighter than normal
B) darker than normal
C) unchanged
D) hypoechoic

Question 6

Unlike digital radiography,conventional imaging media includes:

A) film
B) screens
C) cassettes
D) all of the above

Question 7

Attenuation is the process by which an x-ray beam:

A) is focused
B) is reduced in intensity
C) is reduced in energy
D) exposes a film

Question 8

In 1895,Wilhelm Conrad Roentgen discovered the process of phosphorescence.

Question 9

The emulsion layer of radiographic film contains:

A) tungsten
B) silver halide
C) antimony trisulfide
D) thorium

Question 10

Like all other energy forms of the electromagnetic spectrum,x-rays of every energy level travel at the same speed,the speed of light.

Question 11

Therapeutically,x-rays in the 40 to 300 kVp range are used for:

A) treatment of skin cancers and other superficial tumors
B) the planning of a patient's treatment on the simulator
C) both of the above
D) none of the above

Question 12

Destructive pathologies include:

A) pleural effusion
B) atelectasis
C) edema
D) necrosis

Question 13

X-ray production requires a cathode filament,current sufficient to liberate electrons,an anode target,and an extremely high voltage applied across the tube circuit.

Question 14

Commercially available x-ray tubes generally have focal spots in the range of 0.1 mm to 2.0 mm.

Question 15

The major components of an imaging system on a conventional radiation therapy simulator are an x-ray tube,a fluoroscope,and a CT scanner.

Question 16

A quality radiograph taken 100 cm using 20 mAs could be replicated at 50 cm using:

A) 15 mAs
B) 10 mAs
C) 7 mAs
D) 5 mAs

Question 17

The primary purpose of the anode is to emit liberated electrons in response to an applied current.

Question 18

The quantity of photons in an x-ray beam is directly proportional to:

A) kVp
B) anode temperature rating
C) tube current
D) filtration

Question 19

The predominant x-ray interaction in the diagnostic range is:

A) Compton scatter
B) photoelectric absorption
C) coherent scatter
D) none of the above

Question 20

Interactions at the anode that produce x-rays may be described as:

A) Bremsstrahlung radiation
B) characteristic radiation
C) Compton scattering
D) all of the above
E) a and b only

Question 21

Because of the mobility of the prostate,this imaging modality is often used at the time of treatment to identify the position of the prostate.

A) fluoroscopy
B) ultrasound
C) MRI
D) nuclear medicine

Question 22

Portal imaging on the therapy machine may use which of the following screens?

A) intensifying screens
B) lead
C) copper
D) all of the above

Question 23

Which of the following is responsible for transforming invisible x-ray into energy into visible light?

A) grids
B) glass envelop
C) densitometer
D) intensifying screens

Question 24

In which of the following imaging procedures does an x-ray tube rotate rapidly around the patient?

A) CT
B) MRI
C) fluoroscopy
D) mammography

Question 25

Image fusion as used in the production of PET images may fuse together the PET images with the images of what other imaging modality?

A) ultrasound
B) x-ray
C) CT
D) all of the above

Question 26

Three-dimensional imaging using voxels is present in:

A) MRI
B) CT
C) both of the above
D) neither of the above

Question 27

Which of the following imaging receptors do not use light in capturing the latent image?

A) FPDs
B) TFTs
C) film and screen

Question 28

Which of the following is an advantage of the photostimulatable phosphor plate over conventional x-ray image production?

A) less radiating per exposure
B) postprocessing manipulation of density and contrast
C) no need for radiographic grids
D) higher spatial resolution

Question 29

Which of the following modalities does not use radiation in image production and acquisition?

A) CT
B) nuclear medicine
C) MRI
D) mammography

Question 30

Which of the following may be used in reducing scatter radiation reaching the image receptor?

A) collimation
B) grids
C) filtration
D) all of the above
E) a and b only