摘要
背景:利用CT扫描骨折端,而后进行微分建模分析,是判断骨愈合程度一种行之有效的方法。为获得微分建模仿真的高精度,如何选择最优的CT扫描参数则需要进一步研究分析。目的:在个性化微分建模分析法中,对比不同CT扫描参数对建模精度的影响,验证个性化微分建模法对仿真目标骨段还原的准确性和有效性,探索该方法在判断下肢长管骨骨愈合程度中的研究价值。方法:用猪股骨建立内固定模型,分别采用80 kV-300 mA(A组-低剂量组)、120 kV-335 mA(B组-自动管电流调控系统组)、140 kV-300 mA(C组-手动设置对比组)、140 kV-80 mA(D组-高千伏低毫安组)4组不同曝光条件,进行相同螺距、层厚及环境的扫描,采用相同CT值范围,应用微分建模分析法分别进行目标骨段建模。对CT扫描图像中金属伪影的平均面积、最大面积,微分建模分析后的平均CT值、体积和最大壁厚峰值,以及4组扫描条件下辐射量进行比较,判断减小金属伪影、建模准确度及辐射情况,从而选出最优CT扫描参数。结果与结论:①伪影测量方法结果:A组金属伪影较多,对骨组织遮挡明显,存在漏诊可能;D组金属伪影最少,骨组织周围遮挡少,但图像对比度欠佳,灰雾度较大;而B、C组区别在于图像清晰度,对诊断的准确性基本一致,所以伪影大小排序为:A组>B组>C组>D组;②微分建模分析法结果:B组由于伪影较小,CT值丢失较少,所以仿真出的模型更加接近真实,而且B组采用自动管电流调控系统后,可以明显看出辐射量较小,更加保护患者;③提示B组条件下的CT扫描,可以有效减少金属伪影带来的干扰,更好地保留CT灰度值的原始信息,最大程度地保留目标骨段的密度信息。所以在建立微分建模时,CT自动管电流调控系统为最优的CT扫描参数,不仅可提高个性化微分建模的仿真精度,也增加了计算的准确性。
BACKGROUND:CT scan and differential modeling are used to analyze the fracture end,which is an effective method to judge the degree of bone healing.To obtain the high precision of differential modeling and simulation,how to select the optimal CT scanning parameters needs further research and analysis.OBJECTIVE:To compare the effects of different CT scanning parameters on modeling accuracy in personalized differential modeling analysis,to verify the accuracy and effectiveness of personalized differential modeling in the reduction of simulated target bone segments,and to explore the research value of this method in judging the degree of bone healing of long canals of lower extremities.METHODS:The model of internal fixation was established with porcine femur.Four groups of 80 kV-300 mA(group A-low dose),120 kV-335 mA(group B-automatic tube current control system),140 kV-300 mA(group C-manual setting comparison)and 140 kV-80 mA(group D-high kV and low mA)were used to scan the same object with the same pitch,slice thickness and environment.The scanning data of each group were selected,the same CT value range was used,and the differential modeling analysis method was used to model the target bone segment.The average area and maximum area of metal artifacts in CT scanning images,the average CT value,volume and maximum wall thickness peak after differential modeling analysis,the radiation amount under four groups of scanning conditions were compared to determine the reduction of metal artifacts,modeling accuracy and radiation,so as to select the optimal CT scanning parameters.RESULTS AND CONCLUSION:(1)Artifact measurement method results:In group A,there were many metal artifacts,which obviously obstructed bone tissue,and had a possibility of missed diagnosis.In group D,there were minimal metal artifacts,less occlusion around bone tissue,but poor image contrast and high fog.The difference between group B and group C lay in the clarity of images,and the accuracy of diagnosis was basically the same.Therefore,the order of artifact size was as follows:group A>group B>group C>Group D.(2)Differential modeling analysis results:In group B,because of the smaller artifact and less loss of CT value,the simulated model was more close to the reality.Moreover,group B adopted the automatic tube current control system,which could obviously show that the radiation amount was smaller and more protective for patients.(3)It is confirmed that the CT scan under the condition of group B can effectively reduce the interference caused by metal artifacts,better retain the original information of CT gray value,and retain the density information of the target bone segment to the maximum extent.Therefore,when establishing differential modeling,the CT automatic tube current control system is used as the optimal CT scanning parameter,which not only improves the simulation accuracy of personalized differential modeling,but also increases the accuracy of calculation.
作者
袁新平
邵艳波
吴超
汪剑龄
童梁成
李颖
Yuan Xinping;Shao Yanbo;Wu Chao;Wang Jianling;Tong Liangcheng;Li Ying(Department of Radiology,Air Force Hospital of Eastern Theater Command of Chinese PLA,Nanjing 210002,Jiangsu Province,China;Department of Orthopedics,Air Force Hospital of Eastern Theater Command of Chinese PLA,Nanjing 210002,Jiangsu Province,China;Anhui Medical University,Hefei 230032,Anhui Province,China)
出处
《中国组织工程研究》
CAS
北大核心
2021年第6期912-916,共5页
Chinese Journal of Tissue Engineering Research
基金
南京军区医学科技创新项目(15DX012),项目负责人:李颖
南京市医学科技发展项目(201503008),项目负责人:李颖。
关键词
骨愈合
骨不连
下肢长骨
金属伪影
CT值
微分建模
内固定
bone healing
nonunion
lower limb long bone
metal artifact
CT value
differential modeling
internal fixation
