Work

Ultra-high resolution photon-counting CT of the lung after lung transplantation: should we go for optimal image quality or reduced radiation dose?

Year: 2026

Type: article

Abstract: Objectives As an often-young population with regular CT follow-up, lung transplant (LTX) patients could benefit from both high spatial resolution and lower radiation dose. We compared the image quality of ultra-high-resolution photon-counting CT (UHR-PCCT) with high-resolution energy-integrating-detector CT (HR-EIDCT) at both a normal (IQ100) and a reduced radiation dose (IQ40) in patients after LTX. Methods Hundred patients post-LTX, with an UHR-PCCT (0.4 mm) between Dec-2021 and Aug-2022, and prior HR-EIDCT (1.0 mm) <14 months apart, were included. In 49 patients, PCCT-IQ100 images were compared with previous HR-EIDCT; in 51 patients, PCCT-IQ40 images were compared with previous HR-EIDCT. Image quality was scored using a 5-point Liker scale (−2 to +2) for 7 relevant entities (peripheral airways, micronodules, reticulations, pleural thickening, consolidation, ground glass opacities (GGO), and air-trapping) plus an overall quality impression score. Results For PCCT-IQ100, the median visual grading analysis (VGA) score was significantly better than EIDCT for all structures/abnormalities (median<0; p <0.005) and for most structures/abnormalities in PCCT-IQ40 ( p <0.023). There was no perceived diagnostic impact in either group (median = 2; p ≥ 0.039). Mean dose length product (DLP) was reduced by 33% in PCCT-IQ100 and 73% in PCCT-IQ40 compared to EIDCT ( p <0.0001). Conclusions A significant dose reduction was achieved using the PCCT-IQ40 protocol. Although image quality was best in PCCT-IQ100, image quality in PCCT-IQ40 was non-inferior to EIDCT. Therefore, a significant radiation dose reduction is feasible without compromising image quality. Clinical relevance statement PCCT offers improved image quality while reducing radiation dose significantly. For lung transplant patients, who are often younger and require lifelong, regular follow-up with CT, both improved image quality and lowered radiation dose would be very beneficial. Key Points - LTX patients require long-term follow-up with high-resolution imaging to detect often subtle abnormalities and would benefit from both improved image quality and radiation dose reduction. - Perceived image quality was significantly higher in IQ100-PCCT than EIDCT; a significant further radiation dose reduction was feasible (IQ40-PCCT) without compromising image quality compared to EIDCT.

Source: JHLT Open

DOI: 10.1016/j.jhlto.2026.100547