Add-ons for RealTITracker

PCAMotionDescriptor

PCAMotionDescriptor is an add-on for RealTITracker which implements an optimized PCA-based motion descriptor to characterize in real-time the complex organ deformation during the therapy based on dynamic imaging.

• Goal: The objective is to characterize quantitatively and in real-time individual physiological contributions such as breathing and cardiac activities. The contribution is twofold:
  
  • It offers a robust approach for motion estimation of abdominal organs (optical-flow based algorithms rely on the assumption of conservation of local intensity along the trajectory which can be violated during an interventional procedure. For example, conservation of local intensity can be violated during a thermotherapy procedure because rapid MR-imaging is in general associated with low Signal-To-Noise ratio (SNR). In addition, since the tissue is heated, several MR relevant tissue properties are subject to change during imaging. This leads to local intensity variations, which in turn can be misinterpreted by optical-flow based algorithms as "motion").
    
  • The technique allows correcting on-line motion related artifacts (such as MR-susceptibility variations which generates apparent temperature perturbations).
• Method: The PCA is used to detect, in a preparative learning step, spatio-temporal coherences in the motion of the targeted organ. During hyperthermia, incoherent motion patterns can then be discarded, which allows improving in real-time the robustness of the motion estimation process as well as the compensation of motion related artifacts.
• Installation: To install the PCAMotionDescriptor add-on, decompress the archive in the RealTITracker directory. The file README_PCAMotionDescriptor.TXT included in the archive contains informations regarding the use of the PCAMotionDescriptor add-on.
• How to cite the method: If you use the PCAMotionDescriptor add-on anywhere we would appreciate if you cite the following articles:

  Denis de Senneville B., El Hamidi A., Moonen C. T. W., A direct PCA-based approach for real- time description of physiological organ deformations, IEEE Transactions on Medical Imaging, 2015;34(4):974-982. [Link] [.pdf]

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