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The BRAINs Orientation. Siegfried Schrei Siemens MI Applications. In addition, the anterior commisure and posterior commisure are used for the horizontal orientation in the sagittal plane. - PowerPoint PPT Presentation
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Siegfried SchreiSiemens MI Applications
The BRAINs OrientationThe BRAINs Orientation
Manual Orientation • In addition, the anterior commisure and posterior commisure are
used for the horizontal orientation in the sagittal plane. • The standard orientation calls for lining up the interhemispheric
fissure. This sets the alignment in the coronal and axial planes.
Where are the Anterior and Posterior commissure?
Positioning of Vertical AC and PC Lines
Where are the Anterior and Posterior commissure?
Positioning of Vertical AC and PC Lines (Spect fix distance)
Where are the Anterior and Posterior commissure?
The perfect alignment:
Reperate right and left hemisphere
AC – PC line for correct Axial planes
Coregistration ModalitiesMRI Image or CT images are co registered to the manually reoriented SPECT or PET image by use E.Soft Image Fusion or Syngo 3D Image registration.Manually aligned by visual matching, surface matching or use of anatomical land marks. By far the preferable method is the fully automated alignment based on Mutual Information co registration.When fitting is complete each MRI image is resampled to the SPECT or PET orientation and resolution (128 x 128 Matrix, ca 5 mm cubic voxels).Point to point correspondence with any given set of coordinates referring to the same point in all of the images
Talairach BoundsDefine a Talairach-based atlas for the each scan individually (MRI more easy compared to SPECT)Landmarks used
Right-most extent of the brainLeft-most extent of the brainAnterior-most extent of the brainPosterior-most extent of the brainSuperior-most extent of the brain Inferior-most extent of the temporal lobeAC and PC locations
Talairach Atlas
Talairach atlas coordinate system
Resampled image with overlaid Talairach coordinate system
Talairach RegionsTalairach Atlas warped onto current brain.Various "boxes" assigned to various regionsMeasure volumes of labelled brain regions
Talairach BoxesCyan - Frontal
Blue - TemporalGreen -ParietalRed - Occipital
Pink - CerebellumYellow - Subcortical
Gray - BrainstemGray - Brainstem
Neural NetworkCurrently defines the following regions
CaudatePutamenThalamusCerebellumCerebellar lobes (warping)Hippocampus (requires editing)Globus Pallidus (requires editing)
In the near future will use a warped method for all structures – more valid, less editingWill also add nucleus accumbens and amygdala
Cerebellum LobesCerebellar Lobe Volumes: Uses landmark-based warp for semiautomated measurement of Lobes I through V (anterior lobe), Lobe VI and Crus I of VIIA (superior posterior lobe), Crus II of VIIA through Lobe X (inferior posterior lobe), and the central white matter and output nuclei(corpus medullare).
Talairach Atlas II
What about the cerebellum?Not included in Talairach Atlas
Used for automated gross regional measuresProvides a coordinate system for structure probability
