Deck 21: Digital Radiographic Artifacts

Question 1

Computed radiography cassettes can sit for ____________ between exposures.

A) a few hours
B) a few days
C) up to 1 year
D) an unlimited time

Answer 1

a few days

Question 2

Computer aided diagnosis (CAD) requires the use of ______________________.

A) uncompressed images
B) lossy compression
C) lossless compression
D) Either B or C

Answer 2

uncompressed images

Question 3

The size and number of digital images has to be compressed to permit ___________.

A) transmitting
B) archiving
C) viewing
D) Both A and B

Answer 3

Both A and B

Question 4

Lossy compression reduces data files ______.

A) 10:1
B) 50:1
C) 100:1
D) 1000:1

Question 5

Object artifacts in digital imaging can occur from errors in ___________________. I. x-ray beam collimation
II) histogram selection
III) patient positioning

A) I only
B) II only
C) I and II
D) I, II, and III

Question 6

Lossless compression reduces data files ______.

A) 10:1
B) 50:1
C) 100:1
D) 1000:1

Question 7

Backscatter radiation artifacts can occur more readily in digital imaging because of the ____________________.

A) large data file sizes
B) techniques used
C) highly sensitive receptors
D) partitioning errors

Question 8

Which modality produces the largest image files?

A) Digital or computed radiography
B) Computed tomography
C) Nuclear medicine
D) Digital mammography

Question 9

The largest standard size for a digital imaging plate is _____________.

A) 11 × 14 inches
B) 14 × 17 inches
C) 35 × 35 cm
D) 35 × 43 cm

Question 10

The three classifications of digital imaging artifacts are _______________________.

A) processing, exposure, and handling/storage
B) processing, image receptor, and exposure
C) image receptor, software, and object
D) software, object, and exposure

Question 11

Lossy compression can be used for ____________________.

A) mammography
B) video recordings
C) chest radiographs
D) All of the above

Question 12

A graph of the frequency of occurrence versus digital value intervals is called a(n) ________________.

A) histogram
B) compression
C) digitization
D) algorithm

Question 13

Histogram selection is done ____________________________.

A) automatically during each exposure
B) automatically during post-processing
C) by the radiographer before each exam
D) by the radiographer during post-processing

Question 14

__________________ is done during preprocessing to correct for an irregular pattern over the image.

A) Lossy compression
B) Signal erasure
C) Partitioning
D) Flatfielding

Question 15

Which is/are done to the image during preprocessing?
I.Lossless compression
II.Partitioning
III.Flatfielding

A) I only
B) II only
C) III only
D) I and II

Question 16

A ghost image can occur in digital imaging because of ____________________.

A) supernatural phenomena
B) image blur
C) incomplete erasure
D) backscatter

Question 17

During preprocessing the digital output of the image receptor may need to be manipulated to correct for _________________.

A) dead pixels
B) image blur
C) ghost images
D) radiation fatigue

Question 18

What size is the average CR or DR image file?

A) 10 KB
B) 100 KB
C) 20 MB
D) 200 MB

Question 19

Each anatomical part has an image histogram with a(n) _______________ shape.

A) identical
B) characteristic
C) S-curve
D) round

Question 20

The software correction that equalizes the response of each pixel to a uniform exposure of x-rays is called _______________.

A) lossless compression
B) flatfielding
C) lossy compression
D) histogram selection

Question 21

Creating distinctly collimated margins on all four sides of a DR image is important in preventing ____________________ errors.

A) flatfielding
B) lossless compression
C) histogram analysis
D) archiving

Question 22

It is a safe practice to keep CR cassettes in a "radiation safe" area of an x-ray suite during exams.

Question 23

Artifacts are an acceptable part of digital imaging.