Deck 10: Quality Control for Digital Radiography

Question 1

Each QC system has some sort of registration device that allows direct manual input of demographic and exam information.

Answer 1

False

Question 2

With integrated systems, the receptor needs to be re-exposed to a uniform field to detect the presence of debris.

Answer 2

True

Question 3

As fewer x-rays are used to produce a DR image, the image appears less and less noisy.

Answer 3

False

Question 4

Technologist supervisors learn quickly to count how many films are in the box at the start-of shift, count again at the end-of-shift, and compare against the number of views produced by all exams during the shift.

Question 5

If erasure is inadequate, the previous exposure is superimposed as ____.

A) reusable image media
B) a ghost image
C) a flat field image
D) shading

Question 6

Radiographic images do not include the patient's name and date of birth; instead, a unique patient identification number is used as the file header.

Question 7

In a PACS, a mismatch between the image header and image database information from RIS generates what are known as "exceptions, " "broken studies, " or "orphans."

Question 8

What can build up over time on DR receptors from environmental sources of radiation?

A) residue
B) contrast
C) dust
D) fog

Question 9

Human errors tend to be systematic and predictable.

Question 10

Which calibration for nonuniformity must be repeated on a periodic basis?

A) shading correction
B) flat field
C) reusable image media
D) ghost image

Question 11

What is another name for the flowchart of the steps involved in performing a DR exam?

A) indicator
B) control limit
C) process map
D) metadata

Question 12

Since a key aspect of QA is a visual inspection of the DR image, it is important to consider the capabilities of the QC workstation where we are making decisions.

Question 13

Even with a proper erasure cycle, gross overexposure on the previous exam can leave which of the following?

A) fog
B) screen-film
C) artifacts
D) residual signal

Question 14

Integrated systems have uniform surfaces to capture the radiographic projection, but the efficiency of collection of stimulated emissions is highly nonuniform across the field of view.

Question 15

In DR, demographic and exam data accompany the DR image in an electronic file header.What is this called?

A) process map
B) metadata
C) artifact
D) radiology information system

Question 16

Technologists are quick to learn that physicians are less likely to reject overexposed DR images than underexposed DR images.

Question 17

____ includes all those activities undertaken to get an indication of how well the imaging operation is working.

A) QA
B) AT
C) IT
D) QC

Question 18

____ arise from interference with the projected x-ray beam, image receptor defects, and interference with conversion of the captured projection into a digital image.

A) Artifacts
B) Blurred images
C) Gross positioning errors
D) Duplicate entries

Question 19

With screen-film radiography, which part of the developed film indicates how much radiation has been used in the examination?

A) DR
B) CR
C) kVp
D) OD

Question 20

The DICOM modality worklist (MWL)is a feature designed specifically to take advantage of information that already exists in ____.

A) DR
B) RIS
C) HIS
D) PACS

Question 21

At extremely high contrast, any DR image will appear ____________________.

Question 22

____ is used by imaging scientists and engineers to mean the ratio between the highest detectable radiation level and the lowest detectable radiation level for an image receptor.

A) Latitude
B) Range-of-adjustment
C) Exposure latitude
D) Exposure factor creep

Question 23

When an exam is scheduled for a particular imaging resource, the RIS makes a list of patients available to the DR ____________________ station.

Question 24

Bad electronic images can disappear without a trace; bad films can also disappear, but leave which of the following?

A) ghost
B) residue
C) signature
D) fog

Question 25

____ manufacturers have developed a variety of phantoms and automated tests to assist us in assessing performance on a periodic basis.

A) AT
B) QC
C) CR
D) DR

Question 26

Because verifying every performance parameter before each exam would interfere with clinical operations, periodic measurements assure that the system is properly configured and calibrated and that performance has not ____________________.

Question 27

The Digital Imaging and Communications in Medicine (DICOM)standard specifies the format and content of the ____________________ file.

Question 28

The specific QC tests that are required for digital mammography are those specified by the imaging equipment manufacturer, with the exception of the limitation on maximum radiation dose, which is not more than that allowed for a ____.

A) task allocation matrix
B) GSDF
C) screen-film mammography
D) DR

Question 29

Some errors are the result of improper practice by the technologist, such as incorrect technique factor selection and artifacts from patient clothing or jewelry that interfere with the projected ____________________.

Question 30

____ is reduced by the range of radiation levels that are produced by the range of tissue densities and thicknesses of the anatomy included in the radiographic projection.

A) Latitude
B) Range-of-adjustment
C) Exposure factor creep
D) Exposure latitude

Question 31

The tendency to increase exposure by using higher technique factors than indicated on the technique guide for manual exams and by using plus density settings on AEC exams is an example of ____.

A) range-of-adjustment
B) overexposure
C) rescaling
D) exposure factor creep

Question 32

A simple ____________________ error in selecting the wrong patient or wrong examination from the worklist creates a condition that may be more difficult to detect than a typographical error.

Question 33

Having considered specific QC activities that can help monitor and improve image quality, it is useful to construct a table that identifies each QC task and the party responsible for performing the task.What is this table called?

A) gray scale display function
B) task allocation matrix
C) range-of-adjustment
D) modality worklist

Question 34

For cassette-based systems, the duration of erasure could be too short or the intensity of the erasure could be too low, perhaps from burned out erasure ____________________.

Question 35

When ____________________ in performance is observed, and corrective action is taken, it is important to verify that performance has returned to normal levels.

Question 36

Sometimes improper operation of the ____ system is the underlying cause of a failure to detect the radiation field.

A) CR
B) VOI
C) DR
D) QC

Question 37

The period of ____________________ is important in deciding upon which indicators of changes in performance we are going to monitor routinely.

Question 38

____ analysis is a time-honored method for assessing and improving quality of imaging operations.

A) Reject
B) Residual
C) Signature
D) DR

Question 39

If the operator interface to the machine is extremely complex, ____________________ errors will increase exponentially.

Question 40

Acquiring a ____ image according to the specific conditions of the manufacturer makes it possible to verify uniformity, absence of receptor defects, gain, and the value of the DR exposure indicator.

A) flat-field
B) ghost
C) process map
D) digital

Question 41

The value of the DR exposure indicator is usually visible at the QC ____________________.

Question 42

One of the tasks of the technologist after the DR image is acquired determining whether the image is underexposed or ____________________.

Question 43

Because DR receptors are reused, ____________________ arising from receptor defects, dust and debris that interfere with the collection of light for CR and indirect DR systems, and contaminants such as barium contrast will show up on all subsequent images from that receptor until the problem is corrected.

Question 44

____________________ in DR causes an increase in quantum mottle and a loss of contrast in dense features.

Question 45

Automatic rescaling contributes to a common misconception that in DR exposure ____________________ selection is irrelevant to the appearance of the image.

Question 46

The clinical ____________________ is responsible for equipment life cycle management and is therefore intimately involved in calibrations and service.

Question 47

In the United States, the specifics of QC for digital ____________________ are mandated by the federal government under the Mammography Quality and Standards Act.

Question 48

When the technologist employs nonparallel ____________________, multiple exposure fields on a single cassette-based receptor, or poor centering of the anatomy on the receptor, the algorithm that detects the edges of the radiation field is confounded.

Question 49

A properly calibrated ____________________ indicator could be used to conduct periodic checks of the automatic exposure control (AEC).

Question 50

The one test that can and should be done for every DR image is a(n)____________________ assessment of image quality before release.