比较双能X线吸收测量仪与显微CT显示不同时期去卵巢大鼠胫骨骨量和微结构的特点  

The analysis of bone mass and microarchitecture in ovariectomized rat by dual energy X-ray absorptiometry and microCT

作　　者：范慧洁[1] 戴如春[1] 盛志峰[1] 方玲娜[1] 伍贤平[1] 廖二元[1] 

机构地区：[1]中南大学湘雅二医院代谢内分泌研究所,长沙410011

出　　处：《中华放射学杂志》2008年第4期419-425,共7页Chinese Journal of Radiology

基　　金：国家自然科学基金资助项目（30400514）;卫生部临床学科重点建设资助项目（2004-468-50）

摘　　要：目的应用和比较双能X线吸收测量仪（DXA）与显微CT（μCT）观察不同时期去卵巢（OVX）大鼠胫骨骨量及骨微结构的改变特点。方法40只7个月龄SD大鼠以简单随机抽样方法分为OVX组和假手术（SHAM）组，每组20只，于手术后3周及15周分别处死10只。处死后剥离左侧胫骨行DXA扫描，从胫骨近端开始将胫骨按其长度等分为7个感兴趣区（ROI1～7），计算获得各区域及总体骨密度值。然后将胫骨以4％多聚甲醛固定24h，10％蔗糖溶液洗涤后行斗CT扫描，选取距生长板远端2．5mm、层厚0．4mm骨组织为皮质骨感兴趣区域，选取距生长板远端0．7mm、层厚1．2mm骨组织为松质骨感兴趣区域行三维重组。获取二维最大密度投射图像及三维结构图像，并对感兴趣区的皮质骨和松质骨进行定量分析。所得结果以独立样本t检验进行比较。结果3周时，OVX组大鼠胫骨ROI1区骨密度为（0．2346±0．0280）g／cm^2，显著低于SHAM组（0．2660±0．0199）g／cm^2，（P〈0．05）；15周时，OVX组大鼠胫骨ROI1区及ROI2区骨密度分别为（0．2527±0．0161）及（0．1862±0．0052）g／cm^2，较SHAM组（0．2793±0．0229）及（0．1986±0．0102）g／cm^2有明显下降（P值均〈0．01）。3周时，OVX组大鼠骨皮质骨面积、骨髓腔面积、截面总面积、截面惯性矩分别为（0．4306±0．1308）、（10．31±1．98）、（10．74±2．05）mm^2和（4．101±0．726）mm^4，均明显高于SHAM组（0．3138±0．0621）、（8．44±1．25）、（8．75±1．26）mm^2和（3．485±0．373）mm^4（P值均〈0．05）。至15周时，除皮质骨平均厚度OVX组大鼠为（0．0235±0．0024）mm，低于SHAM组（0．0285±0．0052）mm外（P〈0．05），其余各参数差异均无统计学意义。15周OVX组大鼠左侧胫骨骨丢失敏感区域内皮质骨平均厚度和皮质骨面积为（0．0235±0．0024）mm及（0．2528±0．0367）mm^2，较3周OVX�Objective To observe and compare the changes of bone mass and microarchitecture in ovariectomized rat left tibia by dual energy X-ray absorptiometry （DXA） and microCT （μCT）. Methods Forty seven-month-old SD rats were randomly divided into ovariectomized （OVX） and sham-operated （SHAM） groups, twenty in each group. After killed at 3 weeks and 15 weeks post-surgery, DXA scanning were performed in the left tibia in vitro. The images of left tibia were divided into seven isometric regions of interest （ ROI1--7 ）. When analysis finished, bone density （ BD ） of each ROI and the total bone were determined. The samples were fixed by 4% paraformaldehyde and then placed in the specimen holder filled with deionized water. The sensitive regions for bone mass changes were selected for scanning by Fluro. After scanning, the regions involving 0. 4ram slice thickness and 2. 5ram distance far end from tibial growth plate were selected as the ROI of cortical bone analysis. The regions selected as ROI of cancellous analysis, were involved in 1.2mm slice thickness and 0.7mm distance at the far end from tibial growth plate. After three dimension reconstruction, 2D images of the maximum intensity projection and pictures of 3D microarchitecture were obtained, and BD and microarchitectural parameters were quantitatively identified. All data was statistically processed with SPSS for Windows. Results At the 3rd week, BD of ROI1 in rat left tibia in OVX （0. 2346 ± 0. 0280） g/am^2 was much lower than that （0. 2660 ± 0. 01990） g/am2 in SHAM （P〈0.05）. While at the 15th week, BD of ROI1 （0.2527 ±0.0161） and ROI2 （0.1862 ± 0.0052） g/cm^2 in OVX were both lower than SHAM （0.2793 ±0.0229） and （0. 1986 ±0.0102） g/cm^2 respectively, P 〈 0.01 for both） . Compared with SHAM rat [ cortical area （Ct-Ar） = （0. 3138 ± 0.0621） mm^2, marrow area（Ma-Ar） = （8.44 ± 1.25） mm^2 total area（T-Ar） = （8.75 ± 1.26） mm^2 moment of inertia（Mm） = （ 3. 485 ± 0. 373 ）mm^4

关 键 词：X线 骨密度 体层摄影术 X线计算机 

分 类 号：R686[医药卫生—骨科学]