A novel PCD Micro-CT approach for microstructural analysis of rabbit vertebral bone

To compare vertebral bone microstructure measurements and image quality between a photon-counting detector micro-CT (PCD Micro-CT) system and a conventional micro-CT system (SkyScan 1276) in rabbit vertebral specimens under matched imaging conditions. A retrospective analysis was conducted on 33 New Zealand rabbit vertebral specimens using sequential scanning with PCD Micro-CT (uCT microPCCT, United Imaging Life Science Instrument, China) and Micro-CT (SkyScan1276, Bruker, Germany). Quantitative analysis of bone microstructure using CTAn software on image data acquired from the two devices. Objective image quality was assessed by measuring Signal-to-Noise Ratio (SNR) and Contrast-to-Noise Ratio (CNR) in two defined regions: cortical bone and marrow adipose tissue. Two radiologists with ten years clinical diagnostic experience independently assessed the subjective image quality of the two devices using a standardized 4-point Likert scale and a double-blind method. The PCD Micro-CT system demonstrated significantly higher SNR than the SkyScan 1276 system (18.55 ± 3.57 vs. 15.89 ± 3.91, P < 0.001), whereas CNR was lower (20.32 ± 2.51 vs. 23.73 ± 3.62, P < 0.001). The distribution of subjective image quality scores favored the PCD Micro-CT system, particularly regarding artifact suppression and overall image quality, with good inter-reader agreement. Exploratory analysis of trabecular morphometric parameters (uncorrected for multiple comparisons) identified differences between the two systems in Tb.N, Tb.Th, SMI, DA, Conn, Conn.D, FD, BS/TV, and BS/BV. Under the acquisition and reconstruction settings used in this study, the investigated PCD Micro-CT system demonstrated higher SNR, lower CNR, more favorable subjective image quality scores, and different trabecular bone morphometric measurements than the Micro-CT (SkyScan 1276).