Question 1

Which of the following can occur as a result of a double set of grid lines?&#10;A)Grid misalignment&#10;B)Film fog&#10;C)Static artifacts&#10;D)Moir&#233; effect

Accepted Answer

A double set of grid lines can cause the moiré effect, which appears as a pattern of high-contrast lines superimposed on the anatomical structures of the image. This can be caused by interference between the grid lines and the imaging system's sampling frequency. Grid misalignment can also cause image artifacts, but this is not specific to a double set of grid lines. Film fog and static artifacts are not typically caused by grid lines.

Question 2

Patient motion during exposure results in _____ artifact.&#10;A)a processing&#10;B)an exposure&#10;C)a handling&#10;D)no

Accepted Answer

Patient motion during exposure results in an exposure artifact, which can cause blur or distortion in the image. Processing artifacts are caused by errors in image processing, handling artifacts occur from errors during film handling or processing, and no artifact would be the case if there is no issue during the image acquisition or processing.

Question 3

Which of the following will run in the same direction as that of film travel?&#10;A)Pi lines&#10;B)Hesitation lines&#10;C)Guide shoe marks&#10;D)All of the above

Accepted Answer

Guide shoe marks are caused by the guide shoes that are used to steer the film in the correct direction during processing. Therefore, they will run in the same direction as that of film travel. Pi lines and hesitation lines are caused by other factors such as processing chemicals or equipment malfunctions and may run in different directions than that of the film travel.

Question 4

A chemical fog artifact&#10;A)is an exposure artifact.&#10;B)appears as streaks.&#10;C)results in lower contrast.&#10;D)results in lower optical density.

Accepted Answer

Chemical fog is a processing artifact that results in lower image contrast.

Question 5

Data for determining repeat rates should include at least ____ patients to obtain a statistical sample large enough for valid results.&#10;A)100&#10;B)150&#10;C)250&#10;D)500

Accepted Answer

Generally, a minimum of 250 patients is required to obtain a statistical sample large enough for valid results. Therefore, option C is the best choice.

Question 6

If residual thiosulfate is not properly removed during washing, the radiograph will&#10;A)be underdeveloped.&#10;B)be overdeveloped.&#10;C)turn blue.&#10;D)turn brown.

Accepted Answer

Hyporetention is residual thiosulfate that can cause a brown stain over time.

Question 7

The probability of having a disease given a positive test result is known as&#10;A)accuracy.&#10;B)specificity.&#10;C)positive predictive value.&#10;D)negative predictive value.

Accepted Answer

The positive predictive value (PPV) is the probability of having the disease given a positive test result. It takes into account both the sensitivity and specificity of the test, as well as the prevalence of the disease in the population being tested. Accuracy refers to how closely a test result reflects the true value or status of the condition being tested for, while specificity relates to the proportion of true negatives identified by the test. Negative predictive value (NPV) is the probability of not having the disease given a negative test result.

Question 8

The true positive fraction is referred to as&#10;A)accuracy.&#10;B)sensitivity.&#10;C)specificity.&#10;D)none of the above.

Accepted Answer

The true positive fraction is also called sensitivity, which is a measure of how accurately a test can identify positive cases. It is calculated by dividing the number of true positive results by the sum of true positive and false negative results.

Question 9

Pi lines are so named because they&#10;A)occur at regular intervals.&#10;B)occur on the finished radiograph.&#10;C)appear as a section of pie.&#10;D)None of the above are correct.

Accepted Answer

Pi lines are so named because they occur at regular intervals, forming a series of circles resembling the mathematical symbol for pi. They are caused by a sudden interruption in the X-ray beam during exposure, which can result from various factors such as a momentary power outage or a malfunction in the X-ray machine. Pi lines can be helpful in identifying the cause of a technical error during radiography.

Question 10

Wet pressure sensitization would be classified as _____ artifact.&#10;A)an exposure&#10;B)a processing&#10;C)a handling&#10;D)no

Accepted Answer

Wet pressure sensitization is classified as a processing artifact.

Deck 10: Outcomes Assessment of Radiographic Images