Exam II Term Review

Question 1

Any unwanted image on a radiograph

Answer 1

Artifact

Question 2

Reduction in the energy or number of the primary beam as it passes through anatomic tissue

Answer 2

Attenuation

Question 3

The amount of luminance of a display monitor

Answer 3

Brightness

Question 4

An interaction that occurs with low-energy x-rays, typically below the diagnostic range. The incoming photon interacts with the atom, causing excitation. The x-ray does not lose energy, but changes direction.

Answer 4

Coherent Scattering

Question 5

The loss of energy of the incoming photon when it ejects an outer-shell electron from the atom. The remaining lower-energy x-ray photon changes direction and may leave the anatomic part.

Answer 5

Compton Effect

Question 6

The name for the ejected electron resulting from Compton interactions

Answer 6

Compton Electron / Secondary Electron

Question 7

The ability of the IR to distinguish between objects having similar contrast

Answer 7

Contrast Resolution

Question 8

A process in which some of the x-ray beam is absorbed in the tissue and some passes through (transmits) the anatomic part

Answer 8

Differential Absorption

Question 9

The radiographic misrepresentation of either the size or shape of the anatomic part

Answer 9

Distortion

Question 10

The collection of electronic signal values created by the ionization energies when the exit radiation interacts with an IR

Answer 10

Electronic Data Set

Question 11

The portion of the x-ray beam, containing transmitted & scattered radiation, that leaves the patient and interacts with the IR

Answer 11

Exit Radiation (Remnant Radiation)

Question 12

Dynamic imaging

Answer 12

Fluoroscopy

Question 13

Scattered radiation that reaches the IR and creates unwanted exposure on the radiograph

Answer 13

Fog

Question 14

Images that appear longer than the true object size

Answer 14

Elongation

Question 15

Images that appear shorter than the true object size

Answer 15

Foreshortening

Question 16

The number of different shades of gray that can be stored and displayed on a computer system

Answer 16

Grayscale

Question 17

A device that receives the radiation leaving the patient

Answer 17

Image Receptor

Question 18

The removal of an electron from an atom

Answer 18

Ionization

Question 19

Complete absorption of the incoming x-ray photon. This occurs when the x-ray photon has enough energy to remove an inner-shell electron.

Answer 19

Photoelectric Effect

Question 20

The ejected electron resulting from ionization during the photoelectric effect

Answer 20

Photoelectron

Question 21

Visible brightness on the image as a result of too few photons reaching the IR

Answer 21

Quantum Noise

Question 22

When the IR is extremely overexposed, cannot be properly processed, and the quality is degraded

Answer 22

Saturation

Question 23

Images of objects that appear longer or shorter than the true object size

Answer 23

Shape Distortion

Question 24

Images of objects that appear larger than the true object size

Answer 24

Size Distortion (Magnification)

Question 25

Specifies the intensity of x-rays at a given point in air at a known distance from the focal spot

Answer 25

Air Kerma

Question 26

Number of bits

Answer 26

Bit Depth

Question 27

A light sensitive semi-conducting device that generates an electrical charge when stimulated by light and stores this charge in a capacitor

Answer 27

Charge-Coupled Device (CCD)

Question 28

A method of describing the contrast resolution with the amount of noise apparent in a digital image

Answer 28

Contrast-to-Noise Ratio (CNR)

Question 29

A measurement of the efficiency of an IR in converting the x-ray exposure it receives to a quality radiographic image

Answer 29

Detective Quantum Efficiency (DQE)

Question 30

A charge-collection device with a fixed dimension, and is the functional unit of the detector during signal collection

Answer 30

Detector Elements (DELs)

Question 31

A value that reflects the difference between the desired or target exposure to the IR and the actual exposure to the IR

Answer 31

Deviation Index (DI)

Question 32

Various computer algorithms applied to digital data for the purpose of optimizing the image for display

Answer 32

Digital Image Processing

Question 33

A communication standard for information sharing between PACS and imaging modalities

Answer 33

Digital Imaging and Communications in Medicine (DICOM)

Question 34

A requirement to duplicate all files in a remote location so that recovery is possible in the event of a disaster and the primary files are lost.

Answer 34

Disaster Recovery

Question 35

A post-processing technique that removes superimposed structures to better visualize the anatomic area of interest

Answer 35

Dual-Energy Subtraction

Question 36

A post-processing technique that improves the visibility of small, high-contrast structures.

Answer 36

Edge Enhancement

Question 37

When an outer-shell electron drops into the open position (vacancy) and creates an energy difference

Answer 37

Electron Transition

Question 38

The system for PHI that can be shared outside the facility and among healthcare systems

Answer 38

Electronic Health Record (EHR)

Question 39

A digital record with the ability to store, share, and manage PHI within a single healthcare organization

Answer 39

Electronic Medical Record (EMR)

Question 40

A post-processing technique that functions to make the underexposed areas darker and the over-exposed areas are made lighter

Answer 40

Equalization

Question 41

A numeric value that is displayed on the processed image to indicate the level of exposure received on the IR

Answer 41

Exposure Indicator

Question 42

The percentage of the x-rays reaching the sensitive area of the DEL

Answer 42

Fill Factor

Question 43

Solid-state IRs using a large area active matrix array of electronic components

Answer 43

Flat-Panel Detectors (FPD)

Question 44

The DICOM recommended standard for consistent display characteristics, such as grayscale and image quality

Answer 44

Grayscale Standard Display Function (GSDF)

Question 45

National standards for electronic healthcare transactions and national identifiers for providers, health insurance plans, and employers.

Answer 45

HIPAA

Question 46

Communication standard for medical information

Answer 46

HL7

Question 47

A graphic display of the distribution of pixel values

Answer 47

Histogram

Question 48

The computer analyzing the histogram using processing algorithms and compares it to reference values for the anatomic part imaged

Answer 48

Histogram Analysis

Question 49

Image compression where there is some loss of image data at the end user. Used to decrease transmission time and save on storage space

Answer 49

Irreversible Compression (Lossy)

Question 50

Provide a method of altering the image to change the display of the digital image in a variety of ways

Answer 50

Lookup Tables (LUTs)

Question 51

The emission of visible light from the PSP when stimulated by a high-intensity laser beam

Answer 51

Photostimulable Luminescence

Question 52

The phosphor layer of the imaging CR imaging plate

Answer 52

Photostimulable Phosphor

Question 53

The material of the PSP in the CR imaging plate

Answer 53

Barium Fluorohalide with Europium

Question 54

Smallest component of a matrix

Answer 54

Pixel ("Picture Element")

Question 55

The number of pixels per unit area

Answer 55

Pixel Density

Question 56

The spacing or distance measured from the center of pixel to the next adjacent pixel

Answer 56

Pixel Pitch

Question 57

Image compression where there is no loss of image data at the end user

Answer 57

Reversible Compression (Lossless)

Question 58

Post-processing technique that suppresses quantum noise

Answer 58

Smoothing

Question 59

The practice of diagnostic image interpretation outside the facility

Answer 59

Teleradiology

Question 60

The inherent resolution on an image as a function of image acquisition time

Answer 60

Temporal Resolution

Question 61

A method of describing the strength of the exposure compared to the amount of noise on a digital image

Answer 61

Signal-to-Noise Ratio (SNR)

Question 62

The smallest detail that can be detected on an image

Answer 62

Spatial Resolution

Question 63

Variation in anatomic details imaged as white to black brightness levels that can be defined by line pairs per millimeter

Answer 63

Spatial Frequency

Question 64

A post-processing technique that combines multiple images together into one iamge

Answer 64

Stitching

Question 65

A result of the absorption characteristics of the anatomic tissue radiographed along with the quality of the beam

Answer 65

Subject Contrast