2012 Summer Project Week:Interactive Needle Segmentation

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  Projects List

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  Screenshot of Manual Needle Segmentation (20 minutes)

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  Screenshot of Single Needle Modeled With Tractography Fiducial Seeding Module

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  Screenshot of Multiple Needles Modeled With Tractography Fiducial Seeding Module (Hessian Image Visible)

Key Investigators

• Rutgers: Nabgha Farhat
• BWH: Yi Gao, Neha Agrawal, Nabgha Farhat, Jan Egger, Tina Kapur
• Isomics: Steve Pieper

Objective

The goal of this project is to achieve fast (< 2 minute) interactive segmentation of 5-10 needles from MRI images using Slicer.

Approach, Plan

We will explore different segmentation/editing tools in Slicer to determine which ones can most efficiently segment 2mm needles (10-15 cm long), from MRI scans in which voxels are about 2mm in each dimension. (These needles are not straight lines, and are often placed within a few mm of each other.)

Progress

Needles were effectively modeled from pelvic MRI scans using the Tractography Fiducial Seeding module:

• Scans were cropped to the region of interest
• Hessian images were generated from this data
• Fiducials were placed in regions known to be part of a needle
• The Tractography Fiducial Seeding module was used to generate “tracts” that pass through the fiducial – in this case, the needles

Refinements need to be made to optimize the modeling for brachytherapy needles rather than fiber bundles:

• A sense of “momentum” is needed, so that needles do not abruptly end or change direction in signal voids
• Existing needle and template models (eg, from iGyne) may also be incorporated

Delivery Mechanism

N/A

References