Quantification of lower leg arterial calcifications by high-resolution peripheral quantitative computed tomography.
Quantification of lower leg arterial calcifications by high-resolution peripheral quantitative computed tomography.
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DOI：
10.1016/j.bone.2013.08.006
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发表时间：
2014-01
期刊：
影响因子：
4.1
通讯作者：
Loewe, Christian
中科院分区：
文献类型：
--
作者：
Patsch, Janina M.;Zulliger, Martin A.;Vilayphou, Nicolas;Samelson, Elizabeth J.;Cejka, Daniel;Diarra, Danielle;Berzaczy, Gundula;Burghardt, Andrew J.;Link, Thomas M.;Weber, Michael;Loewe, Christian
血管钙化和骨骼健康似乎通过衰老和亚临床慢性炎症等常见危险因素在病因学上相关。流行病学研究表明，低骨密度 (BMD)、脆性骨折以及冠状动脉和腹主动脉钙化之间存在显着关联。在过去的十年中，高分辨率外周定量计算机断层扫描 (HR-pQCT) 已成为评估外周骨几何形状、密度和微结构的体内研究工具。尽管血管钙化经常作为 HR-pQCT 扫描中的偶然发现被观察到，但它们尚未纳入定量 HR-pQCT 分析中。我们开发了一种半自动算法来量化 HR-pQCT 捕获的小腿动脉钙化 (LLAC)。我们研究的目的是确定 LLAC 测量的有效性和可靠性。 HR-pQCT 扫描缩小至 250 µm 的体素大小。从扫描中减去骨体积后，通过半自动、双阈值种子点分割检测并绘制 LLAC 轮廓。 LLAC 质量（以毫克羟基磷灰石为单位；HA）计算为基于体素的钙化体积 (mm3) 和平均钙化密度 (mgHA/cm3)/1000 的乘积。为了确定有效性，我们将 LLAC 与冠状动脉钙化 (CAC) 进行了比较，通过多排计算机断层扫描 (MDCT) 和 Agatston 评分对 46 名慢性血液透析患者进行量化。此外，我们还研究了 LLAC 与年龄、透析时间、2 型糖尿病、中风病史和心肌梗塞的关系。第二步，我们确定了 LLAC 测量的读者内部和读者之间的可靠性。在有效性研究中，76% 的患者存在 LLAC (>0 mgHA)，78% 的患者存在 CAC (>0 mgHA)。 LLAC 中位数为 6.65 (0.08 – 24.40) mgHA，Agatston 评分表示的 CAC 中位数为 266.3 (15.88 – 1877.28)。我们发现 LLAC 和 CAC 之间存在显着的正相关性 (rho=0.6；p<0.01)。患有 2 型糖尿病 (DM；35%) 和中风病史 (13%) 的透析患者的 LLAC 中位数比没有这些疾病的患者高（DM 高 20.0 倍，p=0.006；中风高 5.1 倍，p=0.047；）。 LLAC 与透析时间呈正相关（rho=0.337，p=0.029），LLAC 与年龄呈正相关趋势（rho=0.289，p=0.053）。可靠性研究得出了 LLAC 测量的良好的读者内和读者间一致性（读者内 ICC=0.999，95% CI=0.998–1.000；读者间 ICC=0.998，95% CI=0.994–0.999）。我们的研究表明，LLAC 测量具有良好的效度和优异的信度。使用 HR-pQCT 同时评估动脉钙化、周围骨几何形状、骨密度和骨微结构应有助于未来对骨血管相互作用以及与心血管事件的潜在关联的研究。
Vascular calcifications and bone health seem to be etiologically linked via common risk factors such as aging and subclinical chronic inflammation. Epidemiologic studies have shown significant associations between low bone mineral density (BMD), fragility fractures and calcifications of the coronary arteries and the abdominal aorta. In the last decade, high-resolution peripheral quantitative computed tomography (HR-pQCT) has emerged as in-vivo research tool for the assessment of peripheral bone geometry, density, and microarchitecture. Although vascular calcifications are frequently observed as incidental findings in HR-pQCT scans, they have not yet been incorporated into quantitative HR-pQCT analyses. We developed a semi-automated algorithm to quantify lower leg arterial calcifications (LLAC), captured by HR-pQCT. The objective of our study was to determine validity and reliability of the LLAC measure. HR-pQCT scans were downscaled to a voxel size of 250 µm. After subtraction of bone volumes from the scans, LLAC were detected and contoured by a semi-automated, dual-threshold seed-point segmentation. LLAC mass (in mg hydroxyapatite; HA) was calculated as the product of voxel-based calcification volume (mm3) and mean calcification density (mgHA/cm3)/1000. To determine validity, we compared LLAC to coronary artery calcifications (CAC), as quantified by multi-detector computed tomography (MDCT) and Agatston scoring in forty-six patients on chronic hemodialysis. Moreover, we investigated associations of LLAC with age, time on dialysis, type-2 diabetes mellitus, history of stroke, and myocardial infarction. In a second step, we determined intra- and inter-reader reliability of the LLAC measure. In the validity study, LLAC were present (>0 mgHA) in 76% of patients, 78% of patients had CAC (>0 mgHA). Median LLAC was 6.65 (0.08 – 24.40) mgHA and median CAC as expressed by Agatston score was 266.3 (15.88 – 1877.28). We found a significant positive correlation between LLAC and CAC (rho=0.6; p<0.01). Dialysis patients with type-2 diabetes mellitus (DM; 35%) and history of stroke (13%) had higher median LLAC than patients without those conditions (DM 20.0 fold greater, p=0.006; Stroke 5.1 fold greater, p=0.047;). LLAC was positively correlated with time on dialysis (rho=0.337, p=0.029), there was a trend towards a positive association of LLAC and age (rho=0.289, p=0.053). The reliability study yielded excellent intra- and inter-reader agreement of the LLAC measure (intra-reader ICC=0.999, 95% CI=0.998–1.000; inter-reader ICC=0.998, 95% CI=0.994–0.999). Our study indicates that the LLAC measure has good validity and excellent reliability. The use of HR-pQCT for the simultaneous evaluation of arterial calcifications, peripheral bone geometry, bone density, and bone microarchitecture should facilitate future research on osteo-vascular interactions and potential associations with cardiovascular events.
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影响因子：
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