Abstract:BACKGROUND:For cone beam computed tomography (CBCT), there has long been a wish to modulate the intensity and distribution of the X-rays to accommodate the patient""s anatomy as the gantry rotates from one projection to another. By doing so, both image artifacts and radiation dose would be reduced. However, the current beam modulation setups, such as dynamic bowtie filters, may be too complex for practical use in clinical applications. OBJECTIVE: This study aimed to investigate a simplified dynamic beam filtration strategy for CBCT imaging to reduce image artifacts and radiation dose. METHODS: In this study, the beam filtration was designed to vary dynamically as the gantry of the CBCT rotates around the object. Specifically, two distinct parts were integrated together: the sheet filter part and the bowtie filter part. The dynamic beam filtration setup has two working schemes, one is a combination of dynamic sheet filter and dynamic bowtie filter, denoted as dynamic filter-dynamic bowtie (DFDB); the other is a combination of dynamic sheet filter and static bowtie filter, denoted as dynamic filter-static bowtie (DFSB). Numerical imaging experiments were performed with respect to three human body parts: shoulder, chest, and knee. In addition, the Monte Carlo simulation platform MC-GPU was used to generate the dose distribution maps. RESULTS: Results showed that the use of the proposed DFDB and DFSB beam filtration schemes can significantly reduce the image artifacts and thus improve the CBCT image quality. Depending on the scanned object, the total radiation dose may be reduced by 30%. CONCLUSIONS: The proposed simple dynamic beam filtration strategy, especially the DFSB approach, might be helpful in the future to improve the CBCT image quality with reduced image artifacts and radiation dose.