Flat-panel detectors (FPDs) are crucial for various applications, including oral imaging, image-guided radiation therapy, and interventional therapy, in both three-dimensional and four-dimensional cone-beam computed tomography (CBCT) imaging.
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Nonetheless, the challenge of balancing high spatial resolution, determined by pixel size, with the constraint of slow data acquisition due to pixel count in flat-panel detectors (FPDs), hinders its progress in advanced CBCT imaging applications that demand both exceptional spatial and temporal resolution. Additionally, the existing FPD technology faces difficulties when attempting to perform dual-energy CBCT imaging for the creation of quantitative material-specific images.
A team of researchers, headed by Professor Yongshuai Ge from the Shenzhen Institute of Advanced Technology at the Chinese Academy of Sciences, has introduced a super-resolution dual-energy CBCT (DE-CBCT) imaging approach named “suRi.” This innovative method relies on a dual-layer FPD.
IEEE Transactions on Medical Imaging published the findings on September 27th, 2023.
Within this approach, sub-pixel shifting (specifically, a half-pixel shift in this study) is employed between the two detector layers to increase the spatial sampling rate of the dual-layer FPD, effectively doubling it during signal acquisition. This technique enables the attainment of high-spatial-resolution CBCT imaging while maintaining a swift signal readout, even with a large detector binning rate.
Furthermore, the research team devised a penalized likelihood material decomposition algorithm that directly reconstructs the high-resolution material components from the dual-energy CBCT projections acquired.
When operating at the identical signal readout speed (detector binning level), the suRi method, as suggested, can enhance image spatial resolution by more than 23% when compared to conventional DE-CBCT imaging based on dual-layer FPD.
Furthermore, suRi enables the direct reconstruction of precise basis images with elevated spatial resolution from the dual-energy projections it acquires.
We believe our method would greatly enhance the imaging performance of dual-energy CBCT systems based on dual-layer-FPD in the future.
Yongshuai Ge, Professor, Shenzhen Institute of Advanced Technology of the Chinese Academy of Sciences
Su, T., et al. (2023) Super resolution dual-energy cone-beam CT imaging with dual-layer flat-panel detector. IEEE Transactions on Medical Imaging. doi:10.1109/TMI.2023.3319668