基于CT图像三维重建测量股骨外翻角

摘要

目的 利用mimics重建股骨的三维图像,通过模拟膝关节置换术来确定解剖轴线机械轴线来测量股骨外翻角的一种方法.方法 利用吉林大学白求恩第三医院住院患者下肢CTA扫描的扫描数据(35岁 男膝关节无疾病、无畸形的成年人).通过使用mimics软件对其CT图像进行二维阈值分割及切割、数据填充等预处理,获得三维股骨模型,并在二维横断面上找到髓内定位杆的入针点,于此点向股骨近端做一直径为4 mm长度为200 mm的圆柱,通过调整圆柱的方向,找到髓内定位杆的最佳位置,可得出进针点及股骨近端该圆柱的中心的三维坐标.将mimics重建的三维模型导入geomagic软件中,通过对股骨的平滑处理,将与髋臼接触的股骨头面拟合成球形,找到该球体的球心三维坐标.使用以上三点的坐标测出其夹角,即外翻角.结果 建立了一种基于CT图像三维重建,准确的获得膝关节轴线的方法.结论 通过此方法可以准确的测出提供术中参考的股骨外翻角,以指导术中截骨,乃至于外翻角术前个体化.%Objective Ushg m in ics reoonstiuctfan 3-din ensional fan oralmodel,to estab lish ameihodmeasurhg fan oral va]gus angle by Sinulating totalknee arftiroplasly to obtain Anatom icalaxis and m echanicalaxial .M ethods we chose lease from bver exten itaes CTA D EOM da1a, (35 year-old ,m ale ,there is no disease ,traun a and deform ity of the low er exten ity ) .The D ICOM in ages w ere in ported into M in ics 10 .0 softer are ,after Two-din enstonal thresholding data pre-filled ,obtain the 3-din ensbnal fan oral reconstruction model,the entty point of the intern edulfray guide rod can be obtained frcm the Two-din ensbnal cross-sectional .And drawing a cylinder (r=4 mm ,length=200 mm ) .Regulating the position of the intern edullary guide rod and obtaining the best position ,we can obtain the Three-din ensional coordiiates of the entry point and the center of proxin al of the intram edullary guide rod .And then fanoralmodelwas in ported into Geanagicall3 .0 softer are .After an ooMig the fanur,the surface of fan oral head which contactwih the acetabulm cbsed fitted into a sphere ,the center of the sphere is the rotational center and three-din ensional coordhates can be find out.Use these three coordinatesm easured valgus angle .Results To establish am eihod obtaimg knee .pintaxis h Three-din ensional reconstruction V irtual environm ent based on CT in ages .Conclusion we can accurate^ measure tie fan oral valgus angle which can be referred in the TKA .