Ch 10 - 02 - Fluoroscopy

Question 1

36- The image intensifier is capable of resolving about __________ while the monitor can resolve about __________.

a. 1 to 2 Lp/mm; 1 to 2 Lp/mm
b. 2 to 3 Lp/mm; 3 to 5 Lp/mm
c. 5 Lp/mm; 5 Lp/mm
d. 5 Lp/mm; 1 to 2 Lp/mm

Answer 1

ANS: D - 5 Lp/mm; 1 to 2 Lp/mm

The image intensifier is capable of resolving about 5 Lp/mm, while the monitor can resolve about 1 to 2 Lp/mm.

Question 2

37- In terms of resolution, the weakest part of the fluoroscopic system is the:

a. image intensifier
b. television monitor
c. camera tube
d. none of the above

Answer 2

ANS: B - television monitor

The television monitor has the least amount of spatial resolution (about 2 Lp/mm) of all the components of the fluoroscopic system.

Question 3

38- Which of the following require the x-ray beam to be in radiographic mode?

a. Cassette spot imaging
b. Film cameras for spot filming
c. Videotape
d. None of the above

Answer 3

ANS: A - Cassette spot imaging

Cassette spot filming uses a regular radiographic cassette, and the tube switches to high mA radiographic mode.

Question 4

39- Which of the following happens while in radiographic mode?

a. X-ray tube switches to high mA
b. X-ray tube switches to low mA
c. Image intensification
d. None of the above

Answer 4

ANS: A - X-ray tube switches to high mA

Cassette spot filming uses a regular radiographic cassette, and the tube switches to high mA radiographic mode.

Question 5

40- This recording system allows the film to be divided into two, four, or more images.

a. Cassette spot imaging
b. Film cameras for spot filming
c. Videotape
d. None of the above

Answer 5

ANS: a. Cassette spot imaging

Cassette spot filming can be set up to record two images per film (two on one), four on one, or more.

Question 6

41- In order to record the dynamic image with image-intensified fluoroscopy, you will need to use:

a. cassette spot filming
b. film cameras for spot filming
c. videotape
d. none of the above

Answer 6

ANS: C - videotape

Videotape provides recording of the moving or dynamic image. The other devices record static images.

Question 7

42- Early versions of digital fluoroscopy used the standard system and added:

a. a different camera
b. an ADC
c. videotape
d. none of the above

Answer 7

ANS: B - an ADC

Early digital fluoroscopy systems added an analog to digital converter between the camera and monitor.

Question 8

43- The analog to digital converter:

a. makes the electrical signal understandable to the computer
b. determines the contrast resolution of the system
c. determines the image matrix
d. all of the above

Answer 8

ANS: D - all of the above

The ADC converts analog data (electrical current) to digital data (1s and 0s). Each ADC has a set number of bits which determine image contrast resolution and the size of the image matrix.

Question 9

44- Digital fluoroscopy is improved by using:

a. a vidicon camera
b. videotape
c. a beam splitting mirror
d. a CCD

Answer 9

ANS: D - a CCD

A CCD used for converting the light image to an electronic image greatly improves digital imaging.

Question 10

45- Which of the following is more light-sensitive?

a. Tube-type camera
b. CCD
c. There is no difference between the two

Answer 10

ANS: B - CCD

The charge-coupled device is more sensitive to the light from the output phosphor; it has a higher DQE.

Question 11

46- Which of the following produces an image with more noise?

a. Vidicon camera
b. CCD
c. There is no difference between the two

Answer 11

ANS: A - Vidicon camera

The vidicon video camera produces an image with more noise, an undesirable quality.
REF: p.275

Question 12

47- The SSD should be no less than __________ for a fixed or stationary fluoroscopy unit and no less than __________ for a mobile fluoro unit (C-Arm).

a. 38 cm; 30 cm
b. 30 cm; 38 cm
c. 30 in; 30 in
d. 30 in; 38 in

Answer 12

ANS: A - 38 cm; 30 cm

The minimum SSD for a stationary fluoro unit is 38 cm; the minimum SSD for a mobile fluoro unit (C-Arm) is 30 cm.

Question 13

48- Which of the following directions can the mobile C-Arm unit move?

a. Move the entire “C” toward or away from the base
b. Pivot the “C” around its axis
c. Slide the “C” along its arc
d. All of the above

Answer 13

ANS: D - All of the above

There are three locks on a C-Arm: One moves the entire “c” toward or away from the base (the equivalent of moving a table side to side); another allows the “c” to pivot on its axis (the equivalent of angling a general radiographic tube head assembly); last allows the “c” to slide along its arc (the equivalent of moving the patient from anteroposterior or posteroanterior positions to oblique to lateral positions without having to move the patient).

Question 14

49- When using the mobile C-Arm unit, the x-ray tube should be positioned under the patient and the image intensifier above the patient because:

a. more convenient to get the unit under the patient’s bed during surgery
b. increases radiographic operator comfort
c. reduce radiation exposure to operator
d. it is easier to move this way.

Answer 14

ANS: C - reduce radiation exposure to operator

When using the mobile C-Arm unit, the x-ray tube should be positioned under the patient and the image intensifier above the patient because it reduces the radiation exposure to the operator.

Question 15

50- In comparison, the vidicon camera tube has __________ spatial resolution, and the CCD requires __________ radiation to produce a good fluoroscopic image.

a. more; more
b. less; less
c. less; more
d. better; less

Answer 15

ANS: B - less; less

In comparison, the vidicon camera tube has less spatial resolution, and the CCD requires less radiation to produce a good fluoroscopic image.

Question 16

51- Use of which of the following systems will result in less radiation dose to the patient?

a. Tube-type camera
b. CCD
c. There is no difference between the two

Answer 16

ANS: B - CCD

Using a CCD device will require less radiation in order to produce a good image, thereby reducing patient exposure.

Question 17

52- The newest fluoroscopy systems use a flat-panel detector:

a. to display the spot images during fluoroscopy
b. to record the overhead images following fluoroscopy
c. in place of the image intensifier
d. in addition to the image intensifier

Answer 17

ANS: C - in place of the image intensifier

The newest fluoroscopy systems use a flat-panel detector in place of the image intensifier.

Question 18

53- Flat-panel detectors for digital fluoroscopic imaging can be the:

a. amorphous silicon indirect capture type
b. photostimulable phosphor plate type
c. amorphous selenium direct capture type
d. A and B
e. A and C

Answer 18

ANS: E - A and C

The indirect and direct capture detectors are suitable for fluoroscopy but the PSP plate is used only in recording static radiographic images.

Question 19

54- Which of the following is easier to move around and allows better access to the patient during a procedure?

a. Conventional image intensifier
b. Flat-panel detector in place of image intensifier
c. There is no difference between the two

Answer 19

ANS: B - Flat-panel detector in place of image intensifier

The flat-panel detector is easier to move around and allows better access to the patient during a procedure because it is significantly less bulky.

Question 20

55- Which of the following does not require any additional devices for spot filming during the fluoroscopic procedure?

a. Conventional image intensifier
b. Flat-panel detector in place of image intensifier
c. There is no difference between the two

Answer 20

ANS: B - Flat-panel detector in place of image intensifier

Because it can easily switch into radiographic mode, the flat-panel detector does not require any additional devices for spot filming during the fluoroscopic procedure.

Question 21

56- Which of the following has a rectangular field of view and a wider dynamic range?

a. Conventional image intensifier
b. Flat-panel detector in place of image intensifier
c. There is no difference between the two

Answer 21

ANS: B - Flat-panel detector in place of image intensifier

The flat-panel detector has a rectangular field of view and a wider dynamic range.

Question 22

57- Which of the following has the possibility of demonstrating veiling glare and pincushion distortion?

a. Conventional image intensifier
b. Flat-panel detector in place of image intensifier
c. There is no difference between the two

Answer 22

ANS: A - Conventional image intensifier

The image intensifier may demonstrate veiling glare and pincushion distortion, negatively affecting the fluoroscopic image’s spatial resolution.

Question 23

58- Which of the following requires more radiation to produce quality fluoroscopic images?

a. Conventional image intensifier
b. Flat-panel detector in place of image intensifier
c. There is no difference between the two

Answer 23

ANS: A - Conventional image intensifier

The flat-panel detector is capable of reducing the radiation dose during fluoroscopy by as much as 50%.

Question 24

59- The x-ray beam used with a digital fluoroscopic unit uses __________ mA and a __________ beam.

a. low; constant
b. high; constant
c. low; pulsed
d. high; pulsed

Answer 24

ANS: D - high; pulsed

The x-ray beam used in digital fluoroscopy uses a high mA (in the hundreds) and a pulsed beam.

Question 25

60- Fluoroscopic equipment should be inspected every: a. week b. month c. 6 months d. year

Answer 25

ANS: C - 6 months Fluoroscopic equipment should be inspected semiannually.

Question 26

61- The radiographer may be responsible for the ______________ inspection of the fluoroscopic equipment for QC purposes. a. performance b. operational c. A and B d. none of the above

Answer 26

ANS: B - operational The radiographer may be responsible for the operational inspection of the fluoroscopic equipment for QC purposes.

Question 27

1- T/F In image-intensified fluoroscopy, the mA used during imaging is considerably lower than in the radiographic mode.

Answer 27

ANS: T - True In image-intensified fluoroscopy, the milliampere (mA) used during imaging is considerably lower (0.5 to 5 mA) than that in the radiographic mode, which is operated at a higher mA of 50 to 1200 mA.

Question 28

2- T/F Each electron that interacts with the output phosphor will result in significantly fewer light photons being produced in comparison to the number of light photons it took to release that electron.

Answer 28

ANS: F - False Each electron that interacts with the output phosphor will result in significantly more light photons being produced in comparison to the number of light photons it took to release that electron.

Question 29

3- T/F The ABC can be slow in responding, seen as a brief delay in the brightness adjustment.

Answer 29

ANS: T - True The automatic brightness control can often be seen lagging behind changes in the intensity of the x-ray exposure to the image intensifier.

Question 30

4- T/F When using magnification mode, the fluoroscopist needs to manually set the exposure factors higher to compensate for the reduced diameter input phosphor.

Answer 30

ANS: F - False The need for increased exposure to the input phosphor when using magnification mode is automatically addressed by the ABC.

Question 31

5- T/F The purpose of a camera tube or CCD is to record the fluoroscopic image.

Answer 31

ANS: F - False The purpose of a camera tube or CCD is to convert the output phosphor image to an electronic signal that can then travel to the television monitor for viewing.

Question 32

6- T/F When a CCD is exposed to light, it generates and briefly stores light energy.

Answer 32

ANS: F - False When a CCD is exposed to light, it generates and briefly stores an electrical charge.

Question 33

7- T/F The beam splitting mirror is never used with fiber optics.

Answer 33

ANS: T - True The beam splitting mirror can only be used with optical lenses because the fiber optics won’t allow the mirror to be introduced.

Question 34

8- T/F The electron gun in the television monitor sends out a steady stream of electrons to activate the fluorescent screen.

Answer 34

ANS: F - False The electron gun in the television monitor sends out a constantly changing stream of electrons to activate the fluorescent screen, allowing display of various levels of brightness.

Question 35

9- T/F Operating the fluoroscope in a pulsed mode will reduce the number of images each second, decrease patient dose, and reduce the visibility of patient motion.

Answer 35

ANS: T - True Operating the fluoroscope in a pulsed mode will reduce the number of images each second, decrease patient dose, and reduce the visibility of patient motion.

Question 36

10- T/F The dose area product (DAP) and cumulative air kerma (kinetic energy released in a mass) provide radiation exposure data and need to be recorded in the patient’s medical record.

Answer 36

ANS: T - True The dose area product (DAP) and cumulative air kerma (kinetic energy released in a mass) provide radiation exposure data and need to be recorded in the patient’s medical record.

Question 37

T/F Most fluoroscopic units today allow for the selection of dose rates, labeled as low, medium, or high (or icons may be used to imply the same).

Answer 37

True

Question 38

T/F A radiation or dose threshold is an important marker that needs to be communicated to the operator.

Answer 38

True