Impact of Dual-Source Spectral Shaping Technology (100/Sn150 kV) on Radiation Dose and Image Quality in Orbital CT

Abstract Background This study investigates the impact of dual-source spectral shaping (DSSS) technology on radiation dose and image quality in orbital CT. Methods A head phantom and the Catphan 600 were scanned using a dual-source CT scanner under a conventional protocol (Group A: 120 kV, CTDI vol = 28.4 mGy) and a DSSS protocol (100/Sn150 kV, Group B: with CTDI vol matching Group A; Group C:84% of Group A's CTDI vol ). Lens doses were measured using thermoluminescent dosimeters, and CT values were recorded. Noise power spectrum (NPS), task-based transfer function (TTF) and detectability index (d′) were calculated. A total of 160 orbital CT examinations were randomly selected, performed under the conventional (Group A) or DSSS protocol(Group C). DLP, scanning length, lens dose, contrast-to-noise ratio (CNR) and gray-scale standard deviation were recorded. Two radiologists evaluated the images using a double-blind method on a 5-point scale. Results In the phantom study, Group C showed significantly lower lens dose than Groups A and Group B ( P = 0.004). Significant differences in CT values, MTF 50% and MTF 10% were observed between Group A and both Groups B and C ( P < 0.001). No significant difference in d’ was found among the three groups ( P = 0.830). In the clinical study, the DSSS protocol resulted in significantly lower lens dose and gray-scale standard deviation compared to the conventional protocol, while CNR increased ( P < 0.001). Subjective image scores for DSSS were all ≥ 4 points. Conclusion DSSS technology can significantly reduces lens dose and improves image quality in orbital CT.