IEEE Transactions on Pattern Analysis and Machine Intelligence
Optical Flow Estimation: An Error Analysis of Gradient-Based Methods with Local Optimization
IEEE Transactions on Pattern Analysis and Machine Intelligence
The existence of geometrical density—image transformations corresponding to object motion
Computer Vision, Graphics, and Image Processing
Principal Warps: Thin-Plate Splines and the Decomposition of Deformations
IEEE Transactions on Pattern Analysis and Machine Intelligence
Computation of component image velocity from local phase information
International Journal of Computer Vision
The computation of optical flow
ACM Computing Surveys (CSUR)
Real-time quantized optimal flow
Real-Time Imaging - Special issue on computer vision motion analysis
Multi-Modality Image Registration Maximization of Mutual Information
MMBIA '96 Proceedings of the 1996 Workshop on Mathematical Methods in Biomedical Image Analysis (MMBIA '96)
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The purpose of this paper is to validate a dose mapping program using optical flow method (OFM), and to demonstrate application of the program in radiotherapy follow-up evaluation. For the purpose of validation, the deformation matrices between four-dimensional (4D) CT data of different simulated respiration phases of a phantom were calculated using OFM. The matrices were then used to map doses of all phases to a single-phase image, and summed in equal time weighting. The calculated dose should closely represent the dose delivered to the moving phantom if the deformation matrices are accurately calculated. The measured point doses agreed with the OFM calculations better than 2% at isocenters, and dose distributions better than 1mm for the 50% isodose line. To demonstrate proof-of-concept for the use of deformable image registration in dose mapping for treatment evaluation, the treatment-planning CT was registered with the post-treatment CT image from the positron emission tomography (PET)/CT resulting in a deformation matrix. The dose distribution from the treatment plan was then mapped onto the restaging PET/CT using the deformation matrix. Two cases in which patients had thoracic malignancies are presented. Each patient had CT-based treatment planning for radiotherapy and restaging fluorodeoxy glucose (FDG)-PET/CT imaging 4-6 weeks after completion of treatments. Areas of pneumonitis and recurrence were identified radiographically on both PET and CT restaging images. Local dose and standard uptake values for pneumonitis and recurrence were studied as a demonstration of this method. By comparing the deformable mapped dose to measurement, the treatment evaluation method which is introduced in this manuscript proved to be accurate. It thus provides a more accurate analysis than other rigid or linear dose-image registration when used in studying treatment outcome versus dose.