A58 Radiation dose reduction with ultra-low dose photon-counting CT for adult ventriculoperitoneal shunt assessment compared to conventional X-ray

<h3>Introduction</h3> Conventional X-rays have so far been used for the radiological monitoring of ventriculoperitoneal (VP) shunts. The cumulative radiation dose is not negligible. Photon counting computed tomography enables good image quality even with low-dose protocols. <h3>Aim of study</h3> The aim of this study was to compare the radiation doses of ultra-low dose PCCT with conventional radiographic VP shunt series in the assessment of shunt pathways in adults. <h3>Method</h3> This retrospective study included 15 ultra-low dose non-contrast PCCT scans in adults (covering the VP shunt pathway from the skull or temporal bone to the ischium) and 52 radiographic VP shunt (each with a.p. skull, a.p. chest, a.p. and lateral abdomen). The effective doses from both imaging modalities were compared using the Mann-Whitney U test. <h3>Results</h3> Ultra-low dose PCCT had a significantly lower radiation dose in terms of effective dose compared to the radiographic shunt series, with an estimated median effective dose of 0.12 mSv (IQR 0.10–0.17 mSv, including the topogram) compared to the estimated median total effective dose for the radiographic VP shunt series of 0.31 mSv (IQR 0.22–0.46 mSv) (p&lt;0.001). This results in a 60% median radiation dose reduction with PCCT compared to conventional shunt series. <h3>Conclusion</h3> Ultra-low dose PCCT provides a significant reduction in radiation dose of approximately 60% compared to conventional X-ray series for assessing VP shunts in adults, with the added benefit of superior visualisation. However, availability and cost must also be considered. <h3>Conflict of Interest</h3> Yes J.R. Kroeger received research support from Philips, support for attending meetings and/or travel from Veryan, honoraria for scientific lectures from GE Healthcare and honoraria for clinical advisory board membership from Siemens Healthineers. J. Borggrefe received honoraria for scientific lectures from Siemens Healthineers and Philips Healthcare.