what is ligase….?!
DESCRIPTION
Segmentation Algorithm. What is LIGASE….?!. CSF. GM. WM. 25 weeks. term. 30 weeks. adult. WM non-uniformity Contrast Changes Brain Size Partial Voluming. GM. noise. WM. CSF. 37 weeks. GM. noise. WM. CSF. 30 weeks. ? ? ? ? ? ? ? ?. ? ? ? ? ?. - PowerPoint PPT PresentationTRANSCRIPT
What is LIGASE….?!
Segmentation Algorithm
CSF
WM
GM
30 weeks term adult25 weeks
WM non-uniformityContrast ChangesBrain Size Partial Voluming
CSF
WMGMnoise
30 weeks
CSF
WM
GM
noise
37 weeks
Methods: Segmentation
? ? ?? ?? ? ?
? ? ? ? ?
CSF
WM
GM
P = Ae- (x- )2 / 2 2
LIGASE
WM min WM maxWM mean
?
reference voxel (Rv)
? test voxel (Tv)
Based on Cutoff value allow Tv to be 1. segmented and left for free growth2. segmented and labeled for restricted growth3. not segmented
For Tv calculate1. Gradient2. Intensity difference from Rv3. WM Probability based on Intensity
Use probability to set1. Gradient cutoff value2. Intensity difference cutoff value
GradientDifference Probability
Difference Cutoff Gradient Cutoff
SegmentationDecision
LIGASE
CSF
WM
GM
WM min WM maxWM mean
P = Ae- (x- )2 / 2 2
mean maxmin
LIGASE
Decreasing values of WM min
LIGASE
CSF
WM
GM
noise GM / noise GMor WM
WM / CSF CSF
GM WM
CSF
LIGASE+
noise
GM / noise
GM
GM / WM
WM
WM / CSF
CSF
unknown
GM / CSF
Anatomy Initial Classification Final Classification
Anatomy LIGASE LIGASEplus
Fin