Deck 6: Medical Imaging

Question 1

11)A quality radiograph taken at 100 cm using 20 mAs could be replicated at 50 cm using which of the following?

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

Answer 1

D
According to the inverse squares law, if the distance is reduced by a factor of 2, the exposure necessary to produce the same image may be reduced by a factor of 4.Likewise, if distance is doubled, the output of the tube must be quadrupled.

Question 2

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

A) Flat panel detectors (FPDs)
B) TFTs
C) Film and screen

Answer 2

A
FPDs require no visible light for image production.With the direct approach of FPDs, the x-rays passing through the patient are converted directly to an electrical signal that generates the digital image.

Question 3

16)Which of the following may be used to reduce the amount of scatter radiation that reaches the image receptor?

A) Collimation
B) Grids
C) Filtration
D) All of the above
E) Both a and b

Answer 3

E
Two significant meAnswer of reducing the amount of scatter radiation that reaches the film are: (1)collimation and (2)grid use.Collimation limits scatter production by minimizing the exposed tissue.Radiographic grids prevent scatter from reaching the film by absorbing the scatter in lead strips.

Question 4

14)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 5

5)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 6

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

A) CT
B) Nuclear medicine
C) MRI
D) Mammography

Question 7

9)Destructive pathologies include which of the following?

A) Pleural effusion
B) Atelectasis
C) Edema
D) Necrosis

Question 8

12)Unlike digital radiography, conventional imaging media includes which of the following?

A) Film
B) Screens
C) Cassettes
D) All of the above

Question 9

7)Which of the following describes the predominant x-ray interaction in the diagnostic range?

A) Compton scatter
B) Photoelectric absorption
C) Coherent scatter
D) None of the above

Question 10

19)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 11

4)Beam quality is affected by changes in which of the following?

A) kVp
B) Potential difference in the x-ray tube
C) Voltage
D) All of the above

Question 12

3)Interactions at the anode that produce x-rays may be described as which of the following?

A) Bremsstrahlung radiation
B) Characteristic radiation
C) Compton scattering
D) All of the above
E) Both a and b

Question 13

1)Therapeutically, x-rays in the 40 to 300 kVp range are used for which of the following?

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 14

2)Components of a modern x-ray tube include which of the following?

A) Cathode filament
B) Rotating anode
C) Glass envelope
D) All of the above

Question 15

13)Which of the following is responsible for transforming invisible x-rays into energy and then into visible light?

A) Grids
B) Glass envelop
C) Densitometer
D) Intensifying screens

Question 16

8)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 17

17)Image fusion as used in the production of positron emission tomography (PET)images may fuse together the PET images with the images of what other imaging modality?

A) Ultrasound
B) X-ray
C) Computed tomography (CT)
D) All of the above

Question 18

18)Three-dimensional imaging using voxels is present in ____________.

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

Question 19

10)Which technical factor has the most effect on radiographic density?

A) mAs
B) kVp
C) Distance
D) All of the above

Question 20

6)Attenuation is the process by which an x-ray beam ___________________.

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

Question 21

22)Who is the discovery of x-rays in 1895 credited to?

A) Wilhelm Conrad Roentgen
B) Theodor Boveri
C) Marie Curie
D) Sir Godfrey Hounsfield

Question 22

23)The emission of liberated electrons is the primary purpose of which of the following?

A) Anode
B) Cathode
C) Target
D) Generator

Question 23

21)Because of the mobility of the prostate, which 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