MO-DE-207A-04: Development and Evaluation Of An Adaptive Deformation-Recovery and Intensity-Correction (ADRIC) CT Reconstruction Technique

Authors


Abstract

Purpose:

Sequential same-patient CT images usually involve deformation-induced and non-deformation-induced voxel intensity changes. An adaptive deformation-recovery and intensity-correction (ADRIC) technique was developed to improve the CT reconstruction accuracy, and to separate deformation from non-deformation-induced voxel intensity changes between sequential CT images.

Methods:

ADRIC views the new CT as a deformation of a prior high-quality CT volume, but with additional non-deformation-induced voxel intensity changes. ADRIC first applies the 2D–3D deformation technique to recover the deformation field between the prior CT volume and the new, to-be-reconstructed CT volume. Using the deformation-recovered new CT volume, ADRIC further corrects the non-deformation-induced voxel intensity changes with an updated algebraic reconstruction technique, enforcing a less stringent total variation smoothing scheme on image difference (‘ART-dTV’). The intensity-corrected new CT volume is subsequently fed back into the 2D–3D deformation process to further correct the residual deformation errors, which forms an iterative loop. By ADRIC, the deformation field and the non-deformation voxel intensity corrections are optimized separately and alternately to reconstruct the final CT. CT myocardial perfusion imaging scenarios were employed to evaluate the efficacy of ADRIC, using both simulated data of the extended-cardiac-torso (XCAT) digital phantom and experimentally acquired porcine data. The reconstruction accuracy of the ADRIC technique was compared to the technique using ART-dTV alone, and to that using 2D–3D deformation alone.

Results:

For the XCAT simulation study, the relative errors of the reconstructed CT by the 2D–3D deformation technique, the ART-dTV technique and the ADRIC technique were 14.64%, 19.21% and 11.90% respectively, by using 20 projections for reconstruction. The corresponding results for the porcine study were 13.61%, 8.78% and 6.80%, respectively.

Conclusion:

The ADRIC technique outperformed both the 2D–3D deformation technique and the ART-dTV technique. The solved deformation field and non-deformation voxel intensity correction can benefit multiple clinical applications, including tumor tracking and treatment outcome analysis.

We acknowledge funding support from the American Cancer Society (RSG-13-326-01-CCE), from the US National Institutes of Health (R01 EB020366), and from the Cancer Prevention and Research Institute of Texas (RP130109).

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