image manipulation. those techniques or processes which modify an image or group of images to...

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