Equipment Operation & Quality Control

Front 1

Advantages of CR/DR include all of the following, except the ability to:

Back 1

Improve geometric detail. -

Geometric detail is controlled only by SID, OID, and focal spot size. These factors are fixed during x-ray exposure.

Front 2

The typical requirements for a fixed x-ray table used for fluoroscopy include the ability to:

Back 2

Move 30 degrees Trendelenburg &Move upright 90 degrees. -

Most x-ray/fluoroscopic equipment is "fixed", meaning it was installed and cannot be moved.

Front 3

In the production of Bremsstrahulung radiation, the incident electron:

Back 3

Is deflected with resulting energy loss. -

"Brems" radiation is 1 of 2 types of x-rays produced at the tungsten target. The incident high-speed electron passing through tungsten atom is attracted by positively charged nucleus; therefore deflected from its course = loss of energy.

Front 4

Which of the following will occur as a result of decreasing the anode target angle?

Back 4

Effective focal spot size will decrease - As target angle decreases (gets steeper/smaller) the effective focal spot becomes smaller = improved detail.

Greater photon intensity toward the cathode side of the x-ray tube - With smaller target angle, anode heel effect increases; photons more absorbed by heel = smaller % of photons at anode and more at the cathode.

Front 5

Which of the following matrix sizes will result in the best spatial resolution?

Back 5

2,048 x 2,048 -

As matrix size is increased, there are more pixels

More pixels = smaller pixels

Smaller pixels = improved resolution

Front 6

Which of the following can be associated with mobile x-ray equipment?

Back 6

Wireless detector

Meet chargeable batteries

High-frequency output

Front 7

Changes in window width in digital imaging result in changes in:

Back 7

Contrast. -

"Windowing" = process of changing contrast and brightness setting on finished image.

"Window width" = controls # of shades of gray in the image (contrast)

"Window level" = image brightness

Front 8

If the primary coil of the high-voltage transformer is supplied by 220V and has 150 turns, and the secondary coil has 75,000 turn, what is the voltage induced in the secondary coil?

Back 8

110kV. -

x 75,000

------- = --------- 150x = 16,500,000

220 150 x = 110,000V

= 100kV

Front 9

Which of the following circuit devices operates on the principle of self-induction?

Back 9

"Self-induction" = characteristic of AC only

Autotransformer - enable tech to vary kilovoltage

Choke coil - type of variable resistor used to regulate filament current

Front 10

All of the following are components of the CT gantry, except:

Back 10

Gantry = includes x-ray tube, detector array, a high-voltage generator, a collimator assembly, slip rings, digital acquistion system, and laser beams.

Console = used only to operate CT machine, select exam protocols, and patient information

Front 11

Radiographers from a particular three-phase, full-wave rectifier x-ray unit were underexposed, using known correct exposures. A synchronous spinning-top test was performed using 100mA, 1/20 second, and 70kV, and a 12-degree arc is observed on the test image. What of the following is the most likely problem?

Back 11

*Because a three-phase, full-wave rectified current would expose a 360-degree arc per second, a 1/20-second exposure should expose an 18-degree arc*

The 1/20-second time station is inaccurate.

Front 12

HVL (half value layer) is influenced by:

Back 12

*The thickness of any absorber that will reduce x-ray beam intensity to 1/2 its original value*

kV level

Total filtration

Front 13

Focal spot size can be evaluated using a

Back 13

Focal spot size accuracy is directly related to the degree of geometric blur; focal spot size increases = blur increases

Slit camera. - measure the physical size of focal spot

Front 14

Which of the following is usually recommended for cleaning PSPs?

Back 14

Should be cleaned monthly.

Anhydrous ethanol. - place small amount on lint-free cloth to clean

Dust on PSP = pinhole artifact

Front 15

Proper care of leaded apparel includes:

Back 15

Periodic check for cracks.

Front 16

Periodic equipment calibration includes testing of the:

Back 16

Focal spot - impact on image sharpness

mA & kV - big impact on quality of finished image

Front 17

An x-ray tube collimator assembly generally includes the following components:

Back 17

Shutters

Mirrors - project size, location, and center of irradiated field

Front 18

Which of the following contributes to inherent filtration?

Back 18

Inherent filtration = "built into" the tube

Before exiting the tube, x-ray photons must pass through:

X-ray tube glass envelope

X-ray tube port window

Front 19

By which of the following can poor screen-film contact be caused?

Back 19

*Perfect contact between the intensifying screens and the film is essential to maintain image sharpness*

Damaged cassette frame

Foreign body in cassette

Warped cassette front

Front 20

A quality assurance program includes checks on which of the following radiographic equipment conditions?

Back 20

Reproducibility - repeated exposures at given technical factors must provide consistent intensity

Linearity - a given mAs, using different mA stations with appropriate exposure time adjustments, provides consistent intensity.

Positive beam limitation - automatic collimation and must be accurate to 2% of SID.