Motion-compensated scheme for sequential scanned statistical iterative dual-energy CT reconstruction

Area of Science:

• Medical Imaging
• Radiology
• Image Reconstruction

Background:

• Dual-energy computed tomography (DECT) excels at tissue discrimination but sequential scanning is prone to motion artifacts.
• Patient motion between scans degrades statistical iterative reconstructions (SIR) in DECT imaging.
• Existing methods struggle to mitigate motion artifacts in sequential DECT scans.

Purpose of the Study:

• To develop and validate a motion-compensation scheme for DECT SIR.
• To reduce image artifacts caused by inter-scan patient motion in DECT.
• To integrate motion correction into the DECT SIR process without compromising accuracy or efficiency.

Main Methods:

• Proposed a motion-compensation scheme integrating a deformation vector field into DECT SIR.
• Estimated the deformation vector field using multi-modality symmetric deformable registration.
• Embedded registration mapping into each iteration of the DECT iterative algorithm.

Main Results:

• Successfully reduced motion artifacts in both simulated and clinical DECT SIR cases.
• Decreased percentage mean square errors in regions of interest from 4.6% to 0.5% (simulated) and 6.8% to 0.8% (clinical).
• Perturbation analysis indicated errors are primarily propagated through the target image.

Conclusions:

• The novel motion-compensation scheme effectively reduces inter-scan motion artifacts in DECT SIR.
• Integration of 3D registration into DECT SIR is feasible for conventional scanners.
• The method enables accurate DECT imaging without significant loss of computational efficiency or accuracy.