Work

Radiation dose comparison of conventional radiography and photon-counting CT for ventriculoperitoneal shunt imaging: A phantom study

Year: 2026

Type: article

Abstract: INTRODUCTION: Ventriculoperitoneal (VP) shunt imaging is a common and often repeated clinical need, which results in cumulative radiation exposure and underscores the necessity to reduce radiation dose in order to minimize long-term risks. The aim of this study was to compare organ-specific radiation exposure between conventional radiography (CR) and ultra-low-dose Photon-Counting computed tomography (PCCT) for VP shunt imaging, with the goal of optimizing radiation dose while preserving diagnostic accuracy. METHODS: Ten phantom measurements each were performed using CR and an optimized ultra-low-dose PCCT protocol, simulating typical multi-region imaging for VP shunt evaluation. Optically stimulated luminescence dosimeters (OSLDs) were positioned on or within radiation-sensitive organs (i.e., eye lenses, thyroid gland, breast, and pelvic organs) of an anthropomorphic phantom to measure absorbed doses. Effective doses for CR and PCCT were estimated using scanner-reported dose values (DAP, DLP) and conversion factors, as well as absorbed doses and ICRP 103 reported tissue weighting factors. Identical anatomical coverage and comparable imaging parameters were applied for both modalities. RESULTS: Ultra-low-dose PCCT resulted in significantly lower radiation doses across all evaluated organs compared with CR (all p < 0.001). Organ-specific dose reductions ranged from 53% to more than 99%, with the largest dose reductions observed for the lenses and the thyroid gland. CONCLUSION: Ultra-low-dose PCCT substantially reduces the radiation exposure of radiosensitive organs in VP shunt imaging compared with standard CR. Given the substantial dose savings and advantages of cross-sectional imaging, PCCT may represent a potentially superior alternative to CR for VP shunt evaluation. IMPLICATIONS FOR PRACTICE: This study highlights the relevance of photon-counting CT as an alternative imaging modality for VP shunt assessment, offering substantial radiation dose reduction alongside potentially improved visualization of shunt components.

Source: Radiography

DOI: 10.1016/j.radi.2026.103400