数字化曲面体层标记位点放大率的实验研究

目的:探讨数字化曲面体层(PTG)的标记位点放大率。方法:以曲面体层机颏托上的U型标记杆及以干燥下颌骨的正常摆放位置为参照,将种植用钢珠按牙弓形态进行唇舌向网点式排布,进行位点设置,按1-8区牙位排列放置钢珠,类似同心圆状辐射排列,位点间距10mm,逐点拍摄,进行投照后在PACS上高清晰显示屏进行测量所得图像的水平向及垂直向数值,对图像进行分析,得出放大率,再进行部位分析,构建体层域。结果:水平向放大率较垂直向为显著,U型标记杆覆盖范围为前牙及双尖牙区,其唇侧水平向放大率均小于1,舌侧水平向放大率均大于1,后磨牙区图像垂直向与水平向均为放大。结论:不同位置的钢珠图像放大率不同,坐标相交点即为同等放大率位置,即位于体层域中心,体层域为显示图像较为真实的扫描区域,体层域唇侧图像水平向缩窄舌侧图像水平向放大,而垂直向均显示放大,变化倍率以水平向为显著(P<0.01),以此来指导临床上对曲面体层片的判读。

Study on Magnification of the Marking Position with Digital Pantomograghy

Objective: To evaluate the magnification of the marking position with digital pantomograghy.Methods: The panoramic machine care on the chin bar and the U-labeled normal to placement of the dry mandible as a reference.It will be arranged according to arch form with the planting ball for labiolingual type to the network,the site settings,from 1-teeth to 8 areas placed ball,similar to the arrangement of concentric circles-like radiation,site spacing 10mm,point by point shooting,set the marking position after the high-definition display on the PACS measured from the horizontal and vertical images to the value of image analysis,the magnification,then the site analysis,and domain physical layer building(Focus Trough).Results: The vertical magnification was significantly higher than the horizontal magnification,U-tag bar coverage for the anterior and premolar region of the labial and horizontal to the amplification rate was less than 1,the tongue side of the zoom rate of was greater than 1 horizontal,vertical and horizontal image after the molar region were amplified.Conclusion: The ball at different positions has different image magnification.The intersection point coordinates of the location is the same magnification,which is in the center of the body layer,physical layer field to display the image scanning area is more real,physical layer level domain to the narrow labial tongue image side of the image to zoom level,and the vertical magnification to show the change in the level of the rate is significantly(P<0.01),in order to guide clinical practice on the panoramic film interpretation.