DIGITAL IMAGE PROCESING
1960 NASA LUNAR AND PLANETARY EXPLORATION
ANALOG DIGITAL ADC
APPLICATION OF DIGITAL IMAGING ULTRASOUND DIGITAL RADIOGRAPHY NUCLEAR MEDICINE CT MRI
RADIOGRAPHY - PAST
TODAY
FLUOROSCOPY IN THE PAST CONVENTIONAL
DIGITAL FLUOROSCOPY
CASTELMAN (1996) CLASSIFICATION OF THE IMAGES BASED ON THEIR FORM OR METHOD OF FORMATION
IMAGES VISIBLE OPTICAL NONVISIBLE IMAGES MATHEMATICAL
ANALOG IMAGE CONTINUOUS IMAGES.
ANALOG IMAGE RADIOGRAPH- CONTINUOUS DISTRIBUTION OF LIGHT INTENSITY AS A FUNCTION OF POSITION ON THE RADIOGRAPH
DIGITAL IMAGE NUMERIC REPRESENTATION OR IMAGES OF OBJECTS
ANALOG TO DIGITAL ADC PROCESSING
ANALOG vs DIGITAL
DIGITAL TO ANALOG DAC
ANALOG PROCESSING INPUT AND OUTPUT IMAGES ARE BOTH ANALOG
DIGITAL PROCESSING INPUT AND OUTPUT IMAGES ARE BOTH DISCRETE
IMAGE DIGITIZATION - ADC SCANNING SAMPLING QUANTIZATION
SAMPLING FREQUENCY
LOW SAMPLING ALIASING ARTIFACT
CT- SIGNAL FROM DETECTORS: ANALOG ANALOG
MRI- SIGNAL FROM DETECTORS: ANALOG ANALOG
PET- SIGNAL FROM DETECTORS: ANALOG ANALOG
BASIC DATA AQUSITION SCHEME IN CT ADC
DETECTORS P.M. TUBE SOLID STATE
DETECTORS
MATRIX - EYE OF THE BEE?!
DIGITAL RADIOGRAPH Y MATRIX
IMAGE RECEPTOR
PIXEL RESOLUTION IN MATRIX 4 x PIXELS 4 x 4 MATRIX
MATRIX PIXEL WHAT MATRIX? 5 X 4 20 PIXELS
HIGH vs LOW RESOLUTION
SPATIAL RESOLUTION
SPATIAL RESOLUTION= FOV/ MATRIX
IMAGE MATRIX SIZES FOR DIFFERENT MODALITIES NUCLEAR MEDICINE CT MRI DR CR 64 X X X X X 2048
DYNAMIC RANGE: THE RANGE OF VALUES OVER WHICH THE SYSTEM CAN RESPOND HOW MANY DIFFERENT SHADES CAN BE DISPLAYED IN THE PIXEL?
DYNAMIC RANGE 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 2 COLORS 4 COLORS 8 COLORS 16 COLORS 32 COLORS 2 X BIT
1 BIT 2 BIT 5 BIT
IMAGE MANIPULATION WINDOWING INVERSION IMAGE SHARPENING
WINDOW CENTER (LEVEL) CONTROLS: IMAGE DENSITY
WINDOW WIDTH CONTROLS: IMAGE CONTRAST
WINDOWING
IMAGE INVERSION
IMAGE SHARPENING
RECENT ADVANCEMENTS
VIRTUAL REALITY
CINE
CT ANGIOGRAPHY