September 26 2008
-- Tri Ngo

A first year has stepped up and volunteered to present. How awesome is that?

Title: Stochastic White Matter Tractography

Abstract: Stochastic Tractography is a Bayesian approach for inferring nerve
fiber tract parameters from DTI (Diffusion Tensor Imaging) data. We
use this framework to calculate the posterior probability of the
existence of tracts given our observations. Additionally, the
Bayesian framework allows the algorithm to infer tracts which pass
through regions with uncertain fiber orientations, previously
unreachable by non-Bayesian methods, thereby revealing more details
about structural connectivity.

We have implemented the algorithm into the ITK medical image analysis
toolkit, an open source NIH supported medical image analysis toolkit.
Additionally we created a user interface which allows the program to
be integrated in the popular 3D Slicer medical image visualization
program. Finally we present some potential clinical studies for the
algorithm.
Location: Clark 110 Homewood

September 12 2008
-- Robert Jacques

Location: Med Campus Talbot Library (Traylor 709)

Title: Towards Real-Time Radiation Therapy:GPU Accelerated Superposition/Convolution

Abstract: We demonstrate the use of highly parallel graphics processing units (GPUs) to accelerate the Superposition/Convolution (S/C) algorithm to interactive rates while reducing the number of approximations. S/C first transports the incident fluence to compute the total energy released per unit mass (TERMA) grid. Dose is then calculated by superimposing the dose
deposition kernel at each point in the TERMA grid and summing the contributions to the surrounding voxels. The TERMA algorithm was enhanced with physically correct multi-spectral attenuation and a novel inverse formulation for increased performance, accuracy and simplicity. Dose deposition utilized a tilted poly-energetic inverse cumulative-cumulative kernel, with the novel option of using volumetric mip-maps to approximate solid angle ray-casting. Exact radiological path ray-casting decreased discretization errors. We achieved a speed-up of 34x-98x over a highly optimized CPU implementation.

Full Paper:
http://www.cse.buffalo.edu/hpmiccai/pdf/HPMICCAI2008-V1.pdf


Laboratory: The Computer Integrated Interventional Systems Laboratory
New page: http://ciis.lcsr.jhu.edu/Research
Old page: http://www.cisst.org/