Hörmann Alina, Neubert Tarek, Campbell Graeme, Wang-Leandro Adriano, Pees Michael, Strube Christina, Merhof Kristina
Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Foundation, Hanover, Germany.
Faculty of Forest Sciences and Forest Ecology, Georg-August University of Göttingen, Göttingen, Germany.
Front Vet Sci. 2025 Jun 13;12:1572887. doi: 10.3389/fvets.2025.1572887. eCollection 2025.
The generation of virtual monoenergetic images using spectral detector computed tomography (SDCT) may facilitate the measurement of bone mineral density (BMD) without the requirement of a phantom. This study has two primary objectives: (1) To compare the BMD values obtained from SDCT maps with those derived from phantom-calibrated values using quantitative computed tomography (QCT) in specific phantom densities and predetermined locations in canine subjects; and (2) to assess the reproducibility, measurement precision, and the potential bias associated with phantom-based measurements.
SDCT examinations of 49 dogs included a phantom containing four hydroxyapatite inserts. BMD values were manually measured in 18 anatomical locations. A linear model was used to convert Hounsfield units to BMD values (mg/cm). A paired Wilcoxon signed-rank test with Bonferroni-correction and Pearson correlation were used for statistical analysis. A -value of ≤ 0.05 was considered significant.
The statistical analysis demonstrated consistently lower BMD values derived from SDCT data within the phantom volume of interest. However, when compared to QCT, higher BMD values were noted across all anatomical sites. QCT data provided BMD values closer to the density of the phantom, while SDCT data appeared to be less sensitive to phantom positioning and body weight. The absolute differences in phantom values were influenced by the number of voxels without completely correcting the generally observed differences in the measured values.
BMD values from both methods demonstrated significant systematic differences, highlighting the need for further research to optimize SDCT for clinical use.
使用光谱探测器计算机断层扫描（SDCT）生成虚拟单能图像可能有助于在无需体模的情况下测量骨矿物质密度（BMD）。本研究有两个主要目标：（1）比较在犬类受试者特定体模密度和预定位置处，从SDCT图像获得的BMD值与使用定量计算机断层扫描（QCT）从体模校准值得出的BMD值；（2）评估基于体模测量的可重复性、测量精度以及潜在偏差。
对49只狗进行SDCT检查，其中包括一个含有四个羟基磷灰石插入物的体模。在18个解剖位置手动测量BMD值。使用线性模型将亨氏单位转换为BMD值（mg/cm）。采用经Bonferroni校正的配对Wilcoxon符号秩检验和Pearson相关性进行统计分析。P值≤0.05被认为具有统计学意义。
统计分析表明，在感兴趣的体模体积内，从SDCT数据得出的BMD值始终较低。然而，与QCT相比，在所有解剖部位均观察到较高的BMD值。QCT数据提供的BMD值更接近体模的密度，而SDCT数据似乎对体模位置和体重不太敏感。体模值的绝对差异受体素数量的影响，且未完全校正测量值中普遍观察到的差异。
两种方法得出的BMD值均显示出显著的系统差异，这突出表明需要进一步研究以优化SDCT用于临床。
