椎体横截面积计算方法改进的实验

Improved method to calculate vertebral body cross-sectional area

背景:目前最为公认的是根据阿基米德定理计算椎体横截面积,但它具有计算过程较复杂、操作不方便等缺点。目的:改进生物力学实验中椎体横截面积的计算方法,拟通过动物实验说明此方法的准确性。设计、时间及地点:随机对照动物实验,于2007-03/07在成都体育学院中心实验室完成。材料:雌性SD大鼠28只,3月龄,体质量(240±20)g,随机分为传统法组和改进法组,每组14只。方法:麻醉大鼠后断头处死,完整取出各组大鼠L3椎体。①传统法计算方法:根据阿基米德定理,椎体的横截面积=椎体体积/椎体高度。椎体体积=(椎体湿重-椎体浸没水中重)/水的密度×重力加速度。②改进法计算方法:将磨制好的椎体竖直置于Microtok纷腾H18扫描仪上,经扫描后存储BMP图像。然后采用Photoshop7.0图形软件处理系统对其进行分析处理,所得结果再经SH专用软件分析计算上下两底面面积,求平均值即为椎体横截面积。主要观察指标:两种方法所测得的大鼠L3椎体横截面积。结论:传统法组大鼠L3椎体横截面积为(7.36±0.48)mm2,而改进法大鼠L3椎体横截面积为(7.63±0.42)mm2。两组椎体横截面积差异无显著性(P=0.5262>0.05)。结果:改进方法计算结果与公认的传统方法同样具有准确性。且简化了计算步骤。

BACKGROUND： Vertebral cross-sectional area is commonly calculated according to Archimedes theorem. However, this procedure is complex and not convenient. OBJECTIVE： To propose an improved method to calculate the cross-sectional area of the vertebra, and validate the correctness of the method. DESIGN, TIME AND SETTING： Randomized controlled animal trial was performed at the Central Laboratory of Chengdu Sport University from March to July 2007. MATERIALS： Twenty-eight 3-month-old male SD rats weighing （240±20） g, were randomly divided into traditional method group and improved method group （n=14）. METHODS： The rats were executed, and L3 was harvested. According to Archimedes theorem, vertebral cross-sectional area （vertebral volume/vertebral height） and vertebralvolume [（vertebra wet weight-vertebra weight in water）/waterdensity× gravity acceleration] were calculated by traditional method. By improved method, the vertebra was placed vertically on Microtok H18 scanner, and BMP images were stored. The data were processed using Photoshop7.0 software, and upper and lower basal surface areas were analyzed using SH private facilities, and the mean value was the vertebral cross-sectional area. MAIN OUTCOME MEASURES： Cross-sectional areas of the third vertebra of all rats by two methods. RESULTS： The cross-sectional areas of the third vertebra by traditional method was （7.36±0.48） mm^2 and the improved method group was （7.63±0.42） mm^2. There were no significant differences between two methods （P=0.526 2 〉 0.05）. CONCLUSION： The improved method exhibits accuracy as traditional method, moreover, it simplifies the procedure, and increases manipuility.