SU‐FF‐I‐39: Development of Clinical Application Platform Using Digital Tomosynthesis for Target Localization

Abstract

Purpose: To develop a workstation for clinical application of digital tomosynthesis (DTS) for real‐time target localization. Specifically, to accelerate the reconstruction both digitally‐reconstructed radiograph (DRR) and DTS using ultra‐fast interpolation capability of graphics hardware. Method and Materials: The developed workstation for real‐time target localization using DTS technology includes image acquisition, image reconstruction, and image comparison. A critical step to implement this technology is its reconstruction speed, especially real‐time generation of reference DTSs which require DRRs. The new generation graphics hardware provides a fast implementation of image interpolation and allows the bi‐linear/tri‐linear interpolation and the other image operations to be accomplished within second. We implemented classical ray‐casting algorithm for 2D DRR and filtered back‐projection (FBP) algorithm for DTS reconstruction on graphics hardware based on OpenGL programming interface. Specifically, planning CT images and on‐board projection images were loaded into the memory of hardware and saved as textures which were projected onto frame‐buffer according to the given geometry of imaging system. The final images were generated by blending multiple textures projected onto the frame‐buffer. Difference images and correlation coefficients between hardware and software DRRs and DTSs were calculated to assess their similarity. Results: The mean errors and their standard deviations of the differences DRR and DTS images are 1.0% ± 1.5% and 1.2% ± 2.1%. The correlation coefficients are 99.9% for DRRs and 99.5% for DTS. The reconstructed efficiency was improved by a factor of 67 for DRR and 13 for DTS. Conclusions: The hardware method provides fast reconstructions of DRR and DTS with visibility of anatomical structures comparable to those generated using software methods.This allows real‐time target localization for image registration between on‐board and reference DTSs in the application platform.