The pattern of trabecular bone microarchitecture in the distal femur of typically developing children and its effect on processing of magnetic resonance images.
The pattern of trabecular bone microarchitecture in the distal femur of typically developing children and its effect on processing of magnetic resonance images.
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典型发育儿童股骨远端骨小梁微结构的模式及其对磁共振图像处理的影响。
DOI：
10.1016/j.bone.2013.11.009
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发表时间：
2014
期刊：
影响因子：
4.1
通讯作者：
Miller,Freeman
中科院分区：
文献类型：
--
作者：
Modlesky,ChristopherM;Whitney,DanielG;Carter,PatrickT;Allerton,BrianneM;Kirby,JoshuaT;Miller,Freeman
磁共振成像（MRI）用于评估人类骨小梁微结构，然而，图像处理可能是劳动密集型和耗时的。本研究的目的之一是确定典型发育儿童股骨远端骨小梁微结构的模式。第二个目的是确定的比例和位置的磁共振图像，需要进行处理，以产生代表性的估计骨小梁microarchitecture.Materials和methodsTwenty-six高分辨率的磁共振图像，立即收集上述生长板在6-12岁的典型发展中的儿童（n = 40）的股骨远端。测量骨小梁微结构[即，使用20个最中心的图像（20 IM）确定股骨远端侧面的表观骨小梁体积/总体积（appBV/TV）、骨小梁数量（appTb.N）、骨小梁厚度（appTb.Th）和骨小梁分离（appTb.Sp）。使用线性回归分析，将来自20 IM的appBV/TV、appTb.N、appTb.Th和appTb.Sp的平均值与来自10个图像（10 IM）、5个图像（5 IM）和3个图像（3 IM）的平均值进行比较，这些图像均匀地分散在整个图像集中，并且来自总图像集中心的一个图像（1 IM）。结果离生长板的距离与appBV/TV（r2= 0.68，p < 0.001）和appTb.N（r2= 0.92，p <0.001）呈强负相关，与appTb.Sp（r2= 0.86，p < 0.001）呈强正相关。距生长板的距离与appTb.Th的关系不是线性的（r2= 0.06，p = 0.28），而是二次曲线，有统计学意义（r2= 0.54，p < 0.001）。10 IM、5 IM、3 IM和1 IM的骨小梁微结构估计值与20 IM的估计值无差异（p> 0.05）。然而，随着使用较小比例的图像来预测20 IM的估计值，相关性的强度逐渐降低（使用10 IM时r2= 0.98至0.99，使用5 IM时r2 = 0.94至0.96，使用3 IM时r2 = 0.87至0.90，使用1 IM时r2 = 0.66至0.72; allp< 0.001）。使用由此产生的数学模型和留一交叉验证分析，从10 IM和5 IM部分图像集估计的骨小梁微结构的措施同意非常好的估计从20 IM. ConclusionsThe研究结果表明，部分磁共振图像集可以用来提供合理的估计骨小梁微结构状态在股骨远端的典型发育儿童。然而，由于骨小梁数量的减少，股骨远端骨小梁的相对量随着与生长板的距离而减少，因此需要仔细定位感兴趣区域并从整个感兴趣区域进行采样。
IntroductionMagnetic resonance imaging (MRI) is used to assess trabecular bone microarchitecture in humans; however, image processing can be labor intensive and time consuming. One aim of this study was to determine the pattern of trabecular bone microarchitecture in the distal femur of typically developing children. A second aim was to determine the proportion and location of magnetic resonance images that need to be processed to yield representative estimates of trabecular bone microarchitecture.Materials and methodsTwenty-six high resolution magnetic resonance images were collected immediately above the growth plate in the distal femur of 6–12 year-old typically developing children (n = 40). Measures of trabecular bone microarchitecture [i.e., apparent trabecular bone volume to total volume (appBV/TV), trabecular number (appTb.N), trabecular thickness (appTb.Th) and trabecular separation (appTb.Sp)] in the lateral aspect of the distal femur were determined using the twenty most central images (20IM). The average values for appBV/TV, appTb.N, appTb.Th and appTb.Sp from 20IM were compared to the average values from 10 images (10IM), 5 images (5IM) and 3 images (3IM) equally dispersed throughout the total image set and one image (1IM) from the center of the total image set using linear regression analysis. The resulting mathematical models were cross-validated using the leave-one-out technique.ResultsDistance from the growth plate was strongly and inversely related to appBV/TV (r2= 0.68,p< 0.001) and appTb.N (r2= 0.92,p< 0.001) and was strongly and positively related to appTb.Sp (r2= 0.86,p< 0.001). The relationship between distance from the growth plate and appTb.Th was not linear (r2= 0.06,p= 0.28), but instead it was quadratic and statistically significant (r2= 0.54,p< 0.001). Trabecular bone microarchitecture estimates from 10IM, 5IM, 3IM and 1IM were not different from estimates from 20IM (p> 0.05). However, there was a progressive decrease in the strength of the relationships as a smaller proportion of images were used to predict estimates from 20IM (r2= 0.98 to 0.99 using 10IM, 0.94 to 0.96 using 5IM, 0.87 to 0.90 using 3IM and 0.66 to 0.72 using 1IM; allp< 0.001). Using the resulting mathematical models and the leave-one-out cross-validation analysis, measures of trabecular bone microarchitecture estimated from the 10IM and 5IM partial image sets agreed extremely well with estimates from 20IM.ConclusionsThe findings indicate that partial magnetic resonance image sets can be used to provide reasonable estimates of trabecular bone microarchitecture status in the distal femur of typically developing children. However, because the relative amount of trabecular bone in the distal femur decreases with distance from the growth plate due to a decrease in trabecular number, careful positioning of the region of interest and sampling from throughout the region of interest is necessary.