Presentation on theme: "Siegfried Schrei Siemens MI Applications The BRAINs Orientation."— Presentation transcript:
Siegfried Schrei Siemens MI Applications The 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)
Horizontal AC to PC line Horizontal AC - PC Line.
Rotate Brain to Anterior and Posterior commissure axis Horizontal AC - PC Line.
Talairach Atlas in Neurogam
The mapped Brain
Where are the Anterior and Posterior commissure? The perfect alignment: Reperate right and left hemisphere AC – PC line for correct Axial planes
Coregistration Modalities MRI 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 Bounds Define a Talairach-based atlas for the each scan individually (MRI more easy compared to SPECT) Landmarks used Right-most extent of the brain Left-most extent of the brain Anterior-most extent of the brain Posterior-most extent of the brain Superior-most extent of the brain Inferior-most extent of the temporal lobe AC and PC locations
Talairach Atlas Talairach atlas coordinate system Resampled image with overlaid Talairach coordinate system
Talairach levels of definition
Talairach Regions Talairach Atlas warped onto current brain. Various "boxes" assigned to various regions Measure volumes of labelled brain regions Talairach Boxes Cyan - Frontal Blue - Temporal Green -Parietal Red - Occipital Pink - Cerebellum Yellow - Subcortical Gray - Brainstem
Talairach vs. Brodmann
The matched regions
T1 and T2 Images Tissue Classified Images
Neural Network Currently defines the following regions Caudate Putamen Thalamus Cerebellum Cerebellar lobes (warping) Hippocampus (requires editing) Globus Pallidus (requires editing) In the near future will use a warped method for all structures – more valid, less editing Will also add nucleus accumbens and amygdala
Neural Network Inputs
Artifical Neural Networks
Cerebellum Lobes Cerebellar 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 measures Provides a coordinate system for structure probability