Radiation dose and signal-to-noise ratio in pediatric head CT: a phantom study comparing photon-counting and energy-integrating detectors

Purpose This study evaluated the relationship between image quality level (IQL), radiation dose, image noise, and signal-to-noise ratio (SNR) in pediatric head CT, comparing energy-integrating detector CT (EID-CT) and photon-counting CT (PCCT) across age-specific phantoms. Methods Head CT scans of 1-, 5-, and 10-year-old anthropomorphic phantoms were performed across a range of IQLs on EID-CT and PCCT. For each IQL, radiation dose, image noise, and SNR were recorded and compared between the two systems. Results PCCT required lower CTDI vol across all phantoms ( p < 0.05). In the clinically relevant IQL-range (IQL 200–300) the 10-year-old phantom showed the greatest relative radiation dose reduction using PCCT (9%), compared to 0.45% in the 1-year-old phantom. Organ doses were highest in the 1-year-old phantom for red bone marrow and skin with no significant differences between the two systems. PCCT offered significantly higher SNR than EID-CT for brain parenchyma ( p < 0.03) and bone ( p = 0.012). Image noise was significantly lower in PCCT for brain parenchyma in the 1- and 5-year-old phantoms ( p < 0.03) and for bone in the 1-year-old phantom ( p = 0.012). Over the full IQL-range (1-300) the average SNR was up to ~ 20% higher for brain parenchyma and ~ 50% higher for bone with PCCT than with EID-CT for all phantoms. Conclusion PCCT offers superior SNR for brain and bone while reducing radiation dose, with the largest radiation dose benefit in older pediatric phantoms, supporting optimized pediatric neuroimaging.