The effect of tube voltage combination on image artefact and radiation dose in dual-source dual-energy CT: comparison between conventional 80/140 kV and 80/150 kV plus tin filter for gout protocol

Objectives: In dual-source CT, dual-energy (DE) performance is affected by various X-ray tube voltage combinations with and without tin filter (Sn). The purpose of this study was to assess the utility of the 80/150 Sn kV voltage combination in terms of image artefact and radiation dose for DECT gout protocol, compared with the conventional 80/140 kV. Methods: Seventy-four patients with suspected gout who underwent dual-source DECT examinations scanned at 80/140 kV (n = 37) and at 80/150 Sn kV (n = 37) were included. Patients' age, sex, and serum uric acid levels were matched between the two groups. The types and incidence of image artefacts and radiation dose were evaluated. Results: The 80/150 Sn kV group had significantly fewer patients with artefacts, compared to the 80/140 kV group [11 (30 %) of 37 vs 35 (94.6 %) of 37, p < 0.001]. Except for the motion artefact, the rest of the artefactsskin, nail bed, submillimetre, motion, vascular, beam-hardening, clumpy artefact along tendonwere significantly less observed in the 80/150 Sn kV acquisitions. The dose-length product (DLP) and effective dose were significantly lower for the 80/150 Sn kV acquisitions compared with the 8s0/140 kV scans (DLP: 104.46 10.66 mGy<bold>cm vs </bold>344.70 56.39 mGy<bold>cm</bold>, p < 0.001; effective dose: 1.04 0.11 mSv vs 3.45 0.56 mSv, p < 0.001). Conclusions: The 80/150 Sn kV voltage combination in dual-source DECT system could be used as one of the artefact reduction methods while reducing radiation dose for gout protocol when compared to the conventional 80/140 kV. Key Points: DECT has emerged as the leading modality for non-invasive diagnosis of gout. Various X-ray tube voltage combinations are now feasible in dual-source DECT. The 80/150 Sn kV acquisition could facilitate artefact reduction in gout protocol.