Deck 2: Digital Imaging Processing Concepts

Question 1

Pixels in a digital image represent the information contained in a volume of tissue in the patient.What is this volume called?

A) bit depth
B) voxel
C) spatial resolution
D) pixel

Answer 1

voxel

Question 2

Digital image pre-processing is a range of techniques that allow the user to change the appearance of a digital image displayed on a monitor for viewing and interpretation.

Answer 2

False

Question 3

The matrix size has an effect on the detail, or bit depth, of the image.

Answer 3

False

Question 4

The processing of images using a computer is called ____.

A) digital radiology
B) image representation
C) diagnostic imaging
D) digital image processing

Question 5

All digital radiography imaging modalities including CR, flat-panel digital radiography, digital mammography, and digital fluoroscopy, utilize digital image processing as a central feature of their operations.

Question 6

A digital image can be described with respect to several characteristics or fundamental parameters, including the matrix, pixels, voxels, and the bit depth.

Question 7

Where do MRIs acquire data from the patient?

A) spatial frequency domain
B) horizontal location domain
C) horizontal frequency domain
D) spatial location domain

Question 8

What can be located using the X-Y coordinate system?

A) X-axis
B) pixel
C) Y-axis
D) spatial location

Question 9

Both past and current day processing technologies include a wide range of image processing algorithms for use in digital radiology.

Question 10

In radiology, what is the viewing task of the radiologist?

A) Manipulate images.
B) Generate digital images.
C) Assess image quality.
D) Detect pathology.

Question 11

The purpose of the ____ class of processing is to generate an image that is more pleasing to the observer.

A) image restoration
B) image analysis
C) image compression
D) image enhancement

Question 12

Digital image processing has become rare in digital radiology departments and is now part of the specialized skills of technologists and radiologists.

Question 13

Geometric operations result in the scaling, sizing, rotation, and translation of images to enhance diagnosis.

Question 14

Image processing operations are intended to change the intensity values of the pixels in the input image and display the resulting changes in the output image, with the goal of changing the characteristics of the image to suit the needs of the observer in order to enhance diagnosis.

Question 15

The pixels that make up the matrix are generally ____.

A) horizontal
B) rectangular
C) square
D) vertical

Question 16

In digital radiography, which of the following is a numerical representation of the patient?

A) analog image
B) analog-to-digital converter
C) photomultiplier
D) digital image

Question 17

Which of the following would generate an output signal in which its intensity varies continuously depending on the location of the light on the image?

A) ADC
B) PMT
C) MRI
D) FOV

Question 18

If the values of the histogram are concentrated in the upper end of the range of values, the image appears dark.

Question 19

What class of digital image processing allows measurements and statistics to be performed, as well as image segmentation, feature extraction, and classification of objects?

A) image analysis
B) image synthesis
C) image compression
D) image restoration

Question 20

There are several operations used in digital image processing to transform an output image into an input image to suit the needs of the human observer.

Question 21

Which process is intended to sharpen an input image in the spatial domain that appears blurred?

A) low-pass filtering
B) convolution
C) masking
D) high-pass filtering

Question 22

A ____ histogram implies more contrast and a ____ histogram will show less contrast.

A) narrow; long
B) wide; narrow
C) narrow; wide
D) wide; long

Question 23

Since digital radiographic detectors have wide exposure latitude and a linear response, an image displayed without processing might appear as a ____.

A) high-contrast image
B) low-contrast image
C) no-contrast image
D) dual-contrast image

Question 24

The inverse ____________________, denoted by FT -1, is used to transform an image in the frequency domain back to the spatial location domain for viewing by radiologists and technologists.

Question 25

____ involves averaging a set of images to reduce image noise.

A) Local processing
B) Windowing
C) Temporal averaging
D) Gray-scale processing

Question 26

The classical sine wave is a continuous function that can be converted into a discrete function, both of which will generate two categories of images, namely, analog and ____________________ images.

Question 27

A more recent form of compression that has been receiving attention in digital diagnostic imaging is that of ____________________ compression.

Question 28

The purpose of ____________________ of digital images is to reduce the size of the image in order to decrease transmission time and reduce storage space.

Question 29

Which of the following processing operations is simple and the one most frequently used in digital diagnostic imaging?

A) gray-scale
B) local
C) contrast
D) point

Question 30

It is important that technologists and radiologists alike become well versed in the nature, scope, and principles of ____________________.

Question 31

Digital imaging modalities such as CT, MRI, diagnostic ultrasound, and nuclear medicine incorporate digital image processing as an essential tool to manipulate and enhance ___________________.

Question 32

Which of the following is intended to reduce noise and the displayed brightness levels of pixels?

A) smoothing
B) convolution
C) filtering
D) masking

Question 33

____ is a process whereby the brightness levels obtained from sampling are assigned an integer (zero or a negative or positive number), called a gray level.

A) Quantization
B) Scanning
C) Digitizing
D) Resolution

Question 34

What is the first step in digitizing an image in which the image is first divided into an array of pixels?

A) sampling
B) quantization
C) resolution
D) scanning

Question 35

A digital image is made up of a 2D array of numbers called a(n)____________________.

Question 36

A digital image is made up of numbers; by definition, the range of the numbers is the ____ and the center of the range is defined as the ____.

A) LUT; WW
B) WW; WL
C) WL; WW
D) LUT; WL

Question 37

The output from a digital radiography detector is an analog (electrical)signal, which is sent to a(n)____________________.

Question 38

The number of bits per pixel is the ____________________.

Question 39

Which of the following is now a routine activity in digital medical imaging, and also an essential tool in the PACS environment?

A) image pre-processing
B) global processing
C) image post-processing
D) low-pass filtering

Question 40

The images obtained in radiology can be represented in two domains, based on how they are acquired: the spatial location domain, and the ____________________ domain.

Question 41

A(n)____________________ is a graph of the number of pixels in the entire image or part of the image having the same gray levels (density values)plotted as a function of the gray levels.

Question 42

Temporal averaging involves averaging a set of images to reduce image ____________________.

Question 43

One popular ____________________ operation is to use the FT in filtering images in the frequency domain rather than in the spatial location domain.

Question 44

The digital image processing technique of unsharp masking uses the ___________________ image produced from the low-pass filtering process and subtracts it from the original image to produce a sharp image.

Question 45

Education programs for both technologists and ____________________ are also beginning to incorporate digital image processing as part of their curriculum.

Question 46

The digital image processing technique known as ____________________ is also intended to change the contrast and brightness of an image.

Question 47

In the act of ____________________, the kernel scans across the entire image, pixel by pixel.

Question 48

The third step in digitizing an image is ____________________.

Question 49

The greater the ____________________, the more accurately the signals from the detectors can be digitized for a faithful reproduction of the original signal.

Question 50

The term ___________________ implies that all the pixels in the entire input image are used to change the value of a pixel in the output image.