Improving single-event proton CT by removing nuclear interaction events within the energy/range detector

Area of Science:

• Medical Physics
• Particle Imaging
• Computational Science

Background:

• Accurate relative stopping power (RSP) reconstruction is vital for proton CT (pCT) imaging.
• Nuclear interactions in detectors can introduce artifacts and reduce image accuracy.
• Current filtering methods in pCT systems have limitations in mitigating these artifacts.

Purpose of the Study:

• To evaluate the performance of different data filters for the US pCT collaboration prototype system.
• To investigate the efficacy of the [Formula: see text]-E filter in removing nuclear interactions within the energy/range detector.
• To compare the RSP accuracy and image quality with and without the [Formula: see text]-E filter.

Main Methods:

• Monte Carlo (MC) simulations using the TOPAS MC platform.
• Acquisition of full pCT scans for water cylinder and tissue insert phantoms.
• Application of [Formula: see text] WEPL filter alone and in combination with energy deposit filters.
• Assessment of the [Formula: see text]-E filter in conjunction with current reconstruction procedures.

Main Results:

• The [Formula: see text] WEPL filter alone did not eliminate all nuclear interaction events, resulting in ring artifacts.
• Existing energy filters applied before the [Formula: see text] WEPL filter showed minimal improvement.
• The [Formula: see text]-E filter, combined with the current protocol, effectively removed systematic fluctuations and improved RSP accuracy.
• Achieved RSP accuracy closely matched simulations without nuclear interactions.

Conclusions:

• The accuracy of the standard [Formula: see text] WEPL filter is sensitive to energy detector uncertainties.
• The [Formula: see text]-E filter demonstrates significant potential for enhancing pCT accuracy by mitigating uncertainties from nuclear interactions.
• This filtering approach shows promise for improving the overall quality of pCT imaging.