2012 Summer Project Week:Overlapping structures

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  Projects List

Key Investigators

• MGH: Greg Sharp
• Isomics: Steve Pieper
• GE: Jim Miller
• Queen's: Andras Lasso

Objective

We are developing capabilities for Slicer to display and manipulate overlapping structures.

Approach, Plan

An initial approach, used in plastimatch, is to represent structure sets as a vector of unsigned characters, with one bit per structure.

Progress

• Discussions of target data types and capabilities:
  • Typically around 100meg for a Head/Neck CT
  • Typically no more than 100 structures
• Goal is to provide lossless representation of original data, with conversion from contours to images for editing and warping
  • Keep original contours as slicer models (view in slices as slice intersections)
  • Provide routines to rasterize contours into label volumes on demand for editing on a per-structure basis
  • Caching if needed
  • Create vector image representation for running warp operations (warp all structures with single evaluation of pixel deformation function)
• Caveats
  • Tilted planes are sometimes used (drawing on native MRI planes, but structures defined on CT)
  • Drawing done on saggital or coronal, would be good to see "caps" of structures
  • How to group structure sets (e.g. to exchange with module, CLI)?

Delivery Mechanism

This work will be delivered to the NA-MIC Kit as a modification of Slicer interals

References

• Greg's progress notes.
• Mockup of UI (http://www.na-mic.org/Wiki/index.php/2012_Winter_Project_Week:RTSS)