Bone quality parameters (BQPs) calculated from computed tomography (CT) and micro-computed tomography (μCT) images have been applied in clinical to diagnose and prevent osteoporotic fractures. However, the BQPs calculated from CT and μCT images are at different scales and incomparable due to the differences in image resolutions and accounted bone compositions. In this study, we proposed a novel method to convert HU values of CT images into the BQPs that were originally calculated using different tools. By using the standard bone composition of human bones, the BQPs of bone volume fractions (BV/TV) and volumetric bone mineral densities (vBMD) of the bones were calculated using different accounted compositions of bones and mathematical relationships defined in this study. In addition, the HU values of the bones were estimated using a parametric physical model and spectrum characteristic parameters. Relationships for converting HU values into BQPs were determined by linear fitting the calculated BQPs and estimated HU values. Cadaveric and patient studies show that the micro-scale bone volumes and macro-scale vBMDs of vertebrae calculated from CT images using the conversion relationships determined by the proposed method were close to those calculated from the μCT images and quantitative CT, respectively, with mean percent errors lower than 5%. The proposed method could be applied in clinical to accurately compute micro- and macro-scale BQPs from CT images for assessing the bone quality of patients.

中文翻译：

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使用参数物理模型和标准骨成分根据计算机断层扫描图像计算微观和宏观骨质量参数


根据计算机断层扫描（CT）和微计算机断层扫描（μCT）图像计算的骨质量参数（BQP）已应用于临床诊断和预防骨质疏松性骨折。然而，由于图像分辨率和骨成分的差异，根据CT和μCT图像计算的BQP具有不同的尺度并且无法比较。在本研究中，我们提出了一种新方法，将 CT 图像的 HU 值转换为最初使用不同工具计算的 BQP。通过使用人体骨骼的标准骨成分，利用不同的骨骼成分和本研究中定义的数学关系计算了骨骼的骨体积分数（BV/TV）和体积骨矿物质密度（vBMD）的BQP。此外，使用参数物理模型和频谱特征参数来估计骨骼的 HU 值。通过线性拟合计算的 BQP 和估计的 HU 值来确定将 HU 值转换为 BQP 的关系。尸体和患者研究表明，使用所提出的方法确定的转换关系从 CT 图像计算出的椎骨微观骨量和宏观 vBMD 分别接近于 μCT 图像和定量 CT 计算的结果，平均百分比误差低于5%。该方法可应用于临床，根据 CT 图像准确计算微观和宏观 BQP，以评估患者的骨质量。