CARLTON - CHAPTER —FLUOROSCOPY

TRUE/FALSE

1.A fluoroscopic exposure cannot be made until the carriage is returned to the full beam intercept position.

ANS:TDIF:Easy

2.Fluoroscopic x-ray tubes are designed to operate for longer periods of time at much lower mA, as compared to a typical diagnostic tube.

ANS:TDIF:Medium

3.The anode of the image intensification system is positioned outside the glass envelope, immediately in front of the output screen.

ANS:FDIF:Easy

4.Flux gain is a measurement of the increase in light photons caused by conversion efficiency of the output screen.

ANS:TDIF:Medium

5.Brightness gain deteriorates with use.

ANS:TDIF:Medium

6.Most automatic brightness control systems monitor the current between the cathode and the anode of the image intensifier to maintain fluoroscopic image density and contrast.

ANS:TDIF:Medium

7.Most automatic brightness control systems have a relatively fast response time.

ANS:FDIF:Medium

8.Quantum mottle is a blotchy or grainy appearance caused by excessive radiation to create a uniform image.

ANS:FDIF:Medium

9.A video monitor is an anode ray tube.

ANS:FDIF:Medium

10.Video monitors can emit low energy x-rays.

ANS:TDIF:Medium

11.The tabletop exposure rate should not exceed 100 R/min.

ANS:FDIF:Medium

12.The minimum source-to-skin distance is 12" for mobile fluoroscopic equipment.

ANS:TDIF:Easy

13.The minimum source-to-skin distance is 15" for stationary fluoroscopic equipment.

ANS:TDIF:Easy

14.Magnification image intensifiers cause decreased patient dose.

ANS:FDIF:Medium

15.The highest energy scatter from the patient during fluoroscopy occurs at a 45-degree angle from the incident beam.

ANS:FDIF:Medium

MULTIPLE CHOICE

1.Fluoroscopy is a ____ radiographic examination.

a. / dynamic / c. / diagnostic
b. / static / d. / more than one of the above

ANS:DDIF:Medium

2.Fluoroscopy is the domain of the ____.

a. / radiographer / c. / radiation physicist
b. / radiologist / d. / radiography student

ANS:BDIF:Medium

3.Fluoroscopy is commonly used for observation of ____.

a. / the heart / c. / the GI tract
b. / a surgical procedure / d. / all of the above

ANS:DDIF:Medium

4.The fluoroscopic x-ray tube and image receptor are mounted on a ____.

a. / carriage / c. / platform
b. / C-arm / d. / camera

ANS:BDIF:Easy

5.The carriage commonly supports the ____.

a. / image intensifier / c. / spot film selector
b. / power drive controls / d. / all of the above

ANS:DDIF:Medium

6.Fluoroscopic mA range is commonly ____ mA.

a. / 0.5 to 5.0 mA / c. / 10.0 to 100 mA
b. / 5.0 to 10.0 mA / d. / 100 to 500 mA

ANS:ADIF:Medium

7.During fluoroscopy, the SOD cannot be less than ____ inches.

a. / 12 / c. / 20
b. / 15 / d. / 40

ANS:BDIF:Medium

8.During fluoroscopic image intensification, the primary x-ray beam exits the patient and strikes the ____ of the image intensifier.

a. / input screen / c. / photocathode
b. / electrostatic lenses / d. / output screen

ANS:ADIF:Medium

9.The input screen absorbs ____ and emits ____.

a. / x-ray photons, light photons / c. / light photons, x-ray photons
b. / x-ray photons, electrons / d. / electrons, x-ray photons

ANS:ADIF:Medium

10.The photocathode absorbs ____ and emits ____

a. / x-ray photons, light photons / c. / light photons, x-ray photons
b. / light photons, electrons / d. / electrons, light photons

ANS:BDIF:Medium

11.Electrostatic lenses are used to accelerate and focus ____.

a. / light photons / c. / electrons
b. / x-ray photons / d. / none of the above

ANS:CDIF:Medium

12.The primary ____ occurs from the acceleration and focusing of the electron beam.

a. / phosphorescence / c. / magnification
b. / minification / d. / brightness gain

ANS:DDIF:Medium

13.The output screen absorbs ____ and emits ____.

a. / electrons, light photons / c. / light photons, electrons
b. / electrons, x-ray photons / d. / light photons, x-ray photons

ANS:ADIF:Medium

14.The input screen is ____ in shape.

a. / oval / c. / concave
b. / elliptical / d. / convex

ANS:CDIF:Medium

15.The shape of the input screen helps to control ____.

a. / distortion / c. / SOD
b. / SID / d. / IOD

ANS:ADIF:Medium

16.The photocathode is composed of ____ metals.

a. / lead-based / c. / photoemissive
b. / photoabsorptive / d. / none of the above

ANS:CDIF:Easy

17.Photoemissive materials absorb ____ and emit ____.

a. / x-ray photons, light photons / c. / light photons, x-ray photons
b. / light photons, electrons / d. / x-ray photons, electrons

ANS:BDIF:Medium

18.Electrostatic lenses are actually ____.

a. / concave optical lenses / c. / planar lenses
b. / convex optical lenses / d. / charged electrodes

ANS:DDIF:Medium

19.The greater the voltage supplied to the electrostatic lenses, the ____ the acceleration and the ____ the focal point to the input screen.

a. / greater, farther / c. / lesser, smaller
b. / greater, closer / d. / greater, larger

ANS:BDIF:Medium

20.Total brightness gain is ____.

a. / a measure of the increase in image intensity
b. / determined by minification gain
c. / determined by flux gain
d. / all of the above

ANS:DDIF:Medium

21.Fluoroscopic resolution will vary according to ____.

a. / minification gain / c. / input and output screen diameter
b. / electrostatic focal point / d. / all of the above

ANS:DDIF:Medium

22.The edge distortion problem in image intensification tubes is called ____.

a. / minification / c. / vignetting
b. / magnification / d. / all of the above

ANS:CDIF:Medium

23.The most common solution for quantum mottle is to ____.

a. / increase the fluoro tube mA
b. / decrease the fluoro tube mA
c. / decrease the efficiency of the input screen
d. / decrease the efficiency of the flux gain

ANS:ADIF:Medium

24.The most commonly used fluoroscopic viewing system is ____.

a. / cine / c. / 70-mm spot film roll
b. / real time video / d. / none of the above

ANS:BDIF:Medium

25.The standard size of a cassette for spot filming is ____.

a. / 8" × 8" / c. / 10" × 10"
b. / 9" × 9" / d. / 12" × 12"

ANS:BDIF:Easy

26.Digitization of the fluoroscopic image permits ____

a. / storage on a computer disc / c. / hard copy printing via laser disc
b. / transfer via Internet / d. / all of the above

ANS:DDIF:Medium

PROBLEM

1.What is the magnification factor for an image viewed with an image intensification tube with an input screen diameter of 23 cm that is using a 13-cm diameter area during magnification?

ANS:

1.8

DIF:Difficult

2.What is the magnification factor for an image viewed with an image intensification tube with an input screen diameter of 23 inches that is using a 10-inch diameter area during magnification?

ANS:

2.3

DIF:Difficult

3.What is the minification gain for an image intensification tube with an input screen diameter of 5 inches and an output diameter of 1 inch?

ANS:

25

DIF:Difficult

4.What is the minification gain for an image intensification tube with an input screen diameter of 10 inches and an output diameter of 2 inches?

ANS:

25

DIF:Difficult

5.What is the total brightness gain for an image intensification tube with a minification gain of 25 and a flux gain of 50?

ANS:

1,250

DIF:Difficult