Metal Artifact Reduction in Dental CBCT Images Using Direct Sinogram Correction Combined with Metal Path-Length...

Area of Science:

• Radiology
• Medical Imaging
• Dental Imaging

Background:

• Metal artifacts significantly degrade dental computed tomography (CT) image quality due to high X-ray absorption from dental implants and crowns.
• Lower tube voltages in dental CT exacerbate artifact severity, often persisting after standard correction methods.
• The direct sinogram correction (DSC) method is effective for mild artifacts but struggles with severe cases.

Purpose of the Study:

• To develop and evaluate a modified DSC method for reducing severe metal artifacts in dental CT images.
• To improve the diagnostic accuracy and readability of dental CT scans affected by metallic objects.

Main Methods:

• Segmentation of metallic objects in CT images to create a metal mask.
• Forward-projection of the metal mask to identify metal traces and compute metal path lengths.
• Application of a modified DSC algorithm with weighting proportional to metal path length for sinogram correction.

Main Results:

• The proposed modified DSC method demonstrated superior performance in reducing severe metal artifacts compared to the original DSC method.
• Successful application of the method to phantom and human dental images acquired at 90 kVp.
• Visual and quantitative improvements in image quality were observed in cases with significant metal artifacts.

Conclusions:

• The modified DSC method offers a promising approach for mitigating severe metal artifacts in dental CT.
• Further validation across diverse CT scan conditions and a larger patient cohort is warranted.
• This technique has the potential to enhance the clinical utility of dental CT imaging.