Digital Radiography Flashcards
Bits- Bitonal image
• In the ____ image, each pixel is assigned a ____ value, in this example 0 for black and 1 for white. The bits are then interpreted and read by the computer to produce an analog version for display and printing
bitonal
tonal
Pixels & Bits
Brightness resolution
The brightness or color value of each pixel is determined by one bit or a group of bits. The more bits used, the higher the ____
Bit depth
The greater the bit depth, the greater the number of ____ (____ or ____)
Digital images may be produced in black & white,(____) grayscale(____) or color(____)
brightness resolution
tones
grayscale
color
1 bit
2-8 bits
8-24 or > bits
1 bit = 2 tones 2 bits=4 tones 3 bits= \_\_\_\_ tones 4 bits= 16 tones 8 bits= \_\_\_\_ tones 16 bits= \_\_\_\_ tones 24 bits= \_\_\_\_ tones
8
256
65536
16.7 million
2 bit image 00 represents \_\_\_\_ 01 \_\_\_\_ 10 \_\_\_\_ 11 \_\_\_\_
black
dark gray
light gray
white
1 bit = \_\_\_\_ measurement • 1 byte= \_\_\_\_ bits • 1 kilobyte(kb)= \_\_\_\_ bytes • 1 Megabyte(MB)= 1000 Kbs • 1 Gigabyte(GB)= 1000 MBs • 1 Terrabyte(TB)= 1000 GBs
smallest
8
1024
Acquisition and display  Digital x-ray systems have 3 distinct parts to consider 1. Image \_\_\_\_ 2. \_\_\_\_ that displays and enhances the image 3. \_\_\_\_, storage, retrieval and \_\_\_\_ 
acquisition
software
integration
telecommunication
CCD – \_\_\_\_ • CMOS/APS - \_\_\_\_ (CMOS) \_\_\_\_ (APS) • PSP – \_\_\_\_ • CID – \_\_\_\_ • Hybrids – Electrical charge converted to \_\_\_\_ • Wireless
charge coupled device complimentary metal oxide semiconductor active pixel sensor photo-stimulable phosphor plate charge injection device CMOS
Noise classification: ____ ____
Signal to Noise Ratio (SNR)
High SNR: ____
Low SNR: ____ resolution

internal/external
random/structure
good resolution
poor resolution
Mach Band Effect
• Involves visual receptors and neural processing of visual signals
•Appearance of ____ but in the regions of tooth not affected by ____
• The effect of this phenomenon on the radiograph is to make dentin appear ____ where it meets enamel
radiolucent
cervical burnout
radiolucent
Logicon caries detector
• While viewing a digital x-ray on-screen, the dentist selects a portion of the tooth surface for diagnosis. The Logicon® Caries Detector automatically:
– ____ any potential carious lesion on the tooth
– Shows ____ of caries into dentin

outlines
progression
DenOptix
• DenOptix Image Cycle using PSP sensors
• Total scanning time: ____
• The time may vary depending on the type of scanner/resolution of the image
1:22 min
Advantages for CID cameras over CCD cameras
CIDs prevent ____ or ____ under extreme lighting conditions
CIDs can read ____ areas of interest within a given frame at higher rates for faster capture and processing
CIDs give UV response down to 185 nm and near-IR response without blooming, fringing or loss of data resolution.
CIDs tolerate ____ environments.

blooming
streaking
multiple
high radiation
Digital Panoramic Imaging
Both ____ based and ____ based systems
PSP based: Dentsply/Gendex Denoptix system

PSP
CCD
Hot Pixel a pixel that reads ____ on ____, and can produce white, red (orange) or green (yellow green) pixels in longer exposures, the longer the exposure the more ____ the hot pixels
Dead Pixels a pixel that reads ____ is always ____ on all exposures. This state produces a ____ pixel in the final image.
Stuck Pixels a pixel that always reads ____ or is always ____ to maximum on all exposures this produces a ____ pixel in the final image.
high
longer exposures
visible
zero
off
black
high
on
white
Interoperability is “the ability of ____ and ____ on different machines from different vendors to communicate”

software
hardware
