Overview Flashcards
Image on the radiograph is a result of xray that
Pass through matter
Absorb
Scattered
Chances to interact
Probability function
Result of xray photons that interact with the film
Black areas
Areas that receive no exposure
White areas
Caused by partial exposure from xray
Grays tones
Uses film and intensifying screen in image formation
Film-Screen Imaging
Enhance the quality of xray
Intensifying screen
Film used a _______ for interpretation
Negathoscope
Properties of radiographic image (film screen imaging)
Density
Contrast
Detail
Distortion
Amount of blackening / amount of exposure
Density
Difference in density
Contrast
How well one can see small structures on the radiograph / sharpness
Detail
Change in size and shape of the object / magnification
Distortion
Image acquisition process that produces an electronic image that can be viewed and manipulated in computer
Digital imaging
2 types of digital acquisition modality
Digital imaging
Uses phosphor plates placed on a cassette for storage of image
Computed Radiography
Stored energy from the plate is read by a reader using a laser and converted to electrical signal
Computed Radiography
Computed radiography was first introduced in the US by
Fuji Medical Systems of Japan
Uses a flat panel detector or charged coupled devices
Cassette-less
Digital Radiography
Two type of digital imaging
Direct capture
Indirect capture
Properties of digital image
Spatial resolution
Contrast resolution
Noise
The ability to distinguish bet two adjacent structure or area on an image
Spatial resolution
Refers to the number of individual pixel values per unit length
Spatial Resolution
Spatial Resolution can be measured using
Pixel size
Line pairs per millimeter(lp/mm)
Distinguish bet differences in intensity of the image
Contrast Resolution
Standard in medical image is
16 bits
In digitized image the _______ determines the contrast resolution
Number of gray scale steps
Digital equivalent of film grain
Image noise
