Micro-CT重建时分析区域变化对颅顶骨骨量参数的影响

Influence of analysis region on parameters of mouse calvarial during micro-CT reconstruction

目的:在分析区域包含整个颅顶骨的前提下,改变颅顶骨显微CT(micro-computed tomography,Micro-CT)扫描后二维图像的重建层数或者位置,比较进行重建后的骨量参数(骨表面积、骨体积)是否出现改变。方法:4日龄小鼠颅顶骨培养后置于含培养液的EP管中,进行连续Micro-CT扫描。根据重建时改变层数或位置来分别分析:(1)996~22层组与800~50层组,分析层数不同(n=3);(2)996~22层组与随机选择层组,分析层数不同(n=3);(3)近边界上缘组与近边界下缘组,分析层数相同(n=3)的骨量参数变化。结果:在分析区域包含整个颅顶骨的前提下:(1)增加或者减少层数导致骨表面积变化(F=47.798,P=0.002),而骨体积无变化(F=7.083,P=0.056)。(2)随机选择层数组与996~22层数组分析比较时骨表面积(F=359.392,P=0.000)、骨体积(F=51.844,P=0.002)均有变化。(3)重建层数相同的前提下,改变分析区域位置时骨表面积(F=0.000,P=0.991)、骨体积(F=0.000,P=0.995)无变化。结论:(1)Micro-CT三维重建时,改变重建层数可影响骨量参数。(2)Micro-CT三维重建时,随机选择重建层数可影响骨量参数。(3)Micro-CT三维重建时,保证分析层数相同而改变空白分析区域的位置不会影响骨量参数。

Objective：To compare the bone parameters of mouse calvarial when the two-dimentional image layers or position of analysis region for reconstruction were changed after Micro-CT scanning,under the precondition that the whole calvarial was included by the analysis region. Methods：The calvarial of 4-day-old mice were scanned consecutively by micro-CT. The bone parameters were compared when the layers or position of analysis region for reconstruction were changed under the precondition that the whole calvarial was included by the analysis region. Results：Under the precondition that the whole calvarial was included by the analysis region,increasing or decreasing the layers of analysis region could accordingly lead to the change of bone surface and bone volume of mouse calvarial. And the bone parameters of the layers selected randomly were significantly different from the parameters of the layers recommended by the NRecon of micro-CT. And there maybe difference when the total layers of analysis region was same but only the position was changed. Conclusion：The change of layers of analysis region for reconstruction can influence the result of bone parameters. Selecting the layers of analysis region randomly will affect the bone parameters. The only change of position without the change of layers may have influence on the bone parameters.