Binary moving-blocker-based scatter correction in cone-beam computed tomography with width-truncated projections:...

Area of Science:

• Medical Physics
• Radiological Imaging
• Computational Imaging

Background:

• Scatter radiation degrades image quality in cone-beam computed tomography (CBCT).
• Existing scatter correction methods can be complex or time-consuming.
• Accurate scatter correction is crucial for applications like image-guided radiation therapy.

Purpose of the Study:

• To introduce and evaluate a binary moving-blocker (BMB) technique for scatter correction in CBCT.
• To assess the impact of BMB on image quality metrics, including spatial nonuniformity and CT number accuracy.
• To demonstrate the potential for reduced acquisition time with the proposed method.

Main Methods:

• A binary moving-blocker (BMB) system with lead strips was employed during CBCT acquisition.
• Scatter maps were derived from blocked projections using 1D B-Spline interpolation/extrapolation.
• Scatter-corrected projections were reconstructed using a compressed-sensing (CS)-based iterative algorithm.

Main Results:

• The BMB technique effectively suppressed scatter-induced artifacts, reducing spatial nonuniformity from 9.1% to 3.1%.
• Root-mean-square error in CT numbers decreased significantly from 30.2 HU to 3.8 HU in regions of interest.
• The method achieved high resolution comparable to benchmark images and improved contrast-to-noise ratio.

Conclusions:

• The proposed BMB-based scatter correction is an effective technique for enhancing CBCT image quality.
• This method allows for scatter correction with width-truncated projections and potentially halves acquisition time.
• The BMB technique holds significant promise for improving CBCT applications in image-guided and adaptive radiation therapy.