image manipulation. those techniques or processes which modify an image or group of images to...
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IMAGE MANIPULATION
IMAGE MANIPULATION
THOSE TECHNIQUES OR PROCESSES WHICH MODIFY AN IMAGE OR GROUP OF IMAGES TO ENHANCE THE VISIBILITY OF USEFUL INFORMATION WHILE SUPPRESSING NOISE OR NON-USEFUL INFO.
WINDOWING
POINT PROCESSING TECHNIQUE
WINDOWING SYNONYMS:
CONTRAST ENHANCEMENT CONTRAST STRETCHING HISTOGRAM MODIFICATION HISTOGRAM STRETCHING
MOST COMMON IMAGE PROCESSING TECHNIQUE IN CT
CONTRAST MANIPULATION
WINDOW WIDTH – WW
CONTROLS CONTRAST IN CT
LARGE NUMBER – LOW CONTRAST LONG SCALE OF CONTRAST
WIDE LATITTUDE
WINDOW LEVEL - WL
CONTROLS DENSITY IN CT
LARGE NUMBER – HIGH DENSITY OBJECTS WITH CT# BELOW WL WILL GET DARKER
WW – 2000, WL 0
CT # 0 + 1000
CT # 0 - 1000
MIDPOINT - O
WINDOW WIDTH
WW
WW
CT # RANGES VARY IN SCANNERS
-1000 TO + 3095 -2048 TO + 6143
WW & WL
+3071
-1024
WW
WW & WL
+3071
-1024
WW
WW & WL
+3071
-1024
WW
WW MANIPULATION
LUNG LIVER PELVIS
NARROWWW
LUNG LIVER PELVIS
WW MANIPULATION
LUNG LIVER PELVIS
MEDIUMWW
LUNG LIVER PELVIS
WW MANIPULATION
LUNG LIVER PELVIS
WIDEWW
LUNG LIVER PELVIS
WL MANIPULATION
LUNG LIVER PELVIS
-1000 +1000WL
WL MANIPULATION
LUNG LIVER PELVIS
-1000 +1000WL
WL MANIPULATION
LUNG LIVER PELVIS
-1000 +1000WL
WW - WIDE 400- 2000 FOR TISSUES OF GREATLY
DIFFERING ATTENUATION WITHIN THE IMAGE
BODY SCANS- 350-600 WW
LUNG – 1000-2000 WW
BONE – 1000 – 2000 WW
WW - NARROW 50-350 FOR DIFFERENT TISSUES OF
SIMILAR DENSITIES WITHIN THE IMAGE
BRAIN - 80-150 WW
LIVER – 100 - 250 WW
WL – WINDOW LEVEL
SHOULD BE CENTERED NEAR THE AVERAGE ATTENUATION OF THE TISSUES OF INTEREST
BODY – 0 TO 60 WLLUNG- -600 TO -800
CONTRAST vs WW
WW CONTRAST
WW CONTRAST
MEDIUM WW – CONTRAST MEDIUM WW – CONTRAST OPTIMIZEDOPTIMIZED
WL 0, WW –1,000
-500 0 +500
1000
500 500
WL +100, WW 800
-300 +100 +500
800
400 400
WL -100, WW 600
-400 -100 +300
600
300 300
WW – 350-600
WL – 0 - 60
40040
WW – 350-600
WL – 0 - 60
40040
WW – 350-600
WL – 0 - 60
40040
WW – 350-600
WL – 0 - 60
40040
WW – 350-600
WL – 0 - 60
60040
WW – 350-600
WL – 0 - 60
60040
WW – 80-150
WL – 0 - 60
8040
WW – 80-150
WL – 0 - 60
14040
WW – 80-150
WL – 0 - 60
15060
WW – 400-2000
WL – -600 TO -750
1500-600
WW – 400-2000
WL – 400-800
1500500
WW – 400-2000
WL – 400-800
1500500
WW – 400-2000
WL – 400-800
1500500
WW – 400-2000
WL – 400-800
1500500
DUAL WINDOW DISPLAY
DIFFERENT WW & WL PROVIDES WELL DEFINED
CONTOURS TO SEPARATE TWO DIFFERENT ANATOMICAL AREAS
VISUALIZATION TOOLS MULTIPLE
WINDOWS
IMAGE MAGNIFICATION
DISTANCE AND ANGLE
COORDINATES
HIGHLIGHTING
CT HISTOGRAM
ROI
ROI AND MAGNIFICATION