automatized methods for coregistration of pet and mr brain images jonny reichwald
DESCRIPTION
Automatized Methods for Coregistration of PET and MR Brain Images Jonny Reichwald. The Synapse. A: axon, B: neurotransmitter 1, C: neurotransmitter 2,. D: synaptic cleft, E: synapse for neurotransmitter 2, F: dendrite. Radioisotopes Isotope Name Half-life (s.) - PowerPoint PPT PresentationTRANSCRIPT
Automatized Methods for Coregistration of PET and MR Brain
Images
Jonny Reichwald
A: axon, B: neurotransmitter 1,C: neurotransmitter 2,
D: synaptic cleft, E: synapse for neurotransmitter 2, F: dendrite.
The Synapse
Radioisotopes
Isotope Name Half-life (s.) [11C] Carbon-11 1223.0 [15O] Oxygen-15 122.24 [13N] Nitrogen-13 597.9 [18F] Flourine-18 6586.2
A: a radioactive decay occurs which emits a positron. B: the positron collides with an electron and emits photons. C: The photons are detected by photomultipliers
A: The decay emits photon pairs at ~ 180 degreesB: The ideal case of a decay resulting in the LOR D.
PET image after reconstruction
MR image
Production of helmet
PET scan
●Resolution●Noise●Reconstruction●Coregistration●Modelling●Ligands
Limiting factors
●Resolution●Noise●Reconstruction●Coregistration●Modelling●Ligands
Limiting factors
Coregistration
●Finding transform●Coregistration algorithms
●Transform●Resampling
Rigid Body
Affine
Projective
Curved
Transform Models
Coregistration
Coregistration
● Manual– Landmarks
● Intrinsic● Extrinsic
– Image overlay● Automatic
– AIR/SPM99● With automatic skull-stripping
– Mutual Information
Voxel probability
Entropy
Kullback-Leibler distance
Mutual Information
PET-PET Registration
Before After
HistogramPET-PET
Before After
Interpolation
● Nearest Neighbour● Linear● (Windowed) Sinc● Splines
General Interpolation
Nearest Neighbour
Linear
Sinc
Splines
Splines
Splines
Time Activity Curve
TAC error
AC-PC Alignment
AC-PC Alignment
Program Platform
● Hba Irix● ECAT6 Solaris● ECAT7 Solaris● ImageJ Java
compatible● SPM Matlab
compatible● PMOD Java compatible
Conclusion
● Use splines or NN for interpolation● AC-PC alignment not important● SPM● PMOD