数字化摄影及图像后处理技术在骨密度测定中的应用

背景：随着直接数字化X射线摄影系统的出现,应用计算机相关知识增加了一些以前普通X射线摄影机不具备的一些后处理程序,为临床骨密度的测定提供了新方法。目的：通过直接数字化X射线摄影系统机拍摄标准骨盆平片,利用其强大后处理功能,通过测量股骨颈、ward三角及股骨大转子的象素密度,找出简单易行测定骨密度的新方法。方法：随机选择105份标准骨盆直接数字化X射线平片,按年龄以60岁为标准,分为实验组（≤60岁）和对照组（〉60岁）。根据标准骨盆平片制定测量股骨颈密度的三点、ward三角一点及股骨大结节三点。对两组女性患者的股骨颈、股骨大转子及股骨颈ward三角象素密度均数分别进行t检验,观察两个年龄段股骨颈、股骨大转子及股骨颈ward三角密度值分布情况。结果与结论：对照组股骨颈象素密度为945.59±174.70,大转子象素密度为712.67±196.89,ward三角象素密度为873.70±195.17;实验组股骨颈象素密度为779.03±125.79,大转子象素密度为526.22±127.93,ward三角象素密度为668.30±131.19。两组间比较差异有显著性意义（P〈0.05）。提示,通过测量直接数字化X射线摄影系统骨盆平片上骨质的象素密度可以作为骨密度测定方法之一,且操作简便,易于临床掌握和运用,不需患者行二次医疗检查。

Application of digital radiography and image processing technique in the determination of bone mineral density

BACKGROUND： With the appearance of direct digital X-ray camera system digital radiography（DR）, computer-related knowledge is applied to increase post-processing procedures, which provides a new method for the determination of clinical bone mineral density.OBJECTIVE： To explore a new method measuring bone mineral density by measuring pixel density of femoral neck, ward＇s triangle and greater trochanter of femur with digital DR’s powerful post-processing function on standard pelvic plain film.METHODS： According to age, 105 pelvic direct digital X-ray plain films were randomly divided into experimental group （≤60 years old） and control group （60 years old）. Three spots on femoral neck density, one spot on ward triangle, and three spots on femur large nodule were measured according to standard formulation of the pelvic plain films. T test was used to examine femoral neck, femoral greater trochanter and femoral neck ward triangle mean pixel density between two groups female patients, respectively. The density distribution of femoral neck, femoral greater trochanter and femoral neck ward triangle between two groups were observed. RESULTS AND CONCLUSION： In control group, pixel density of the femoral neck （945.59±174.70）, greater trochanter pixel density （712.67±196.89）, ward triangle pixel density （873.70±195.17）; in experimental group, neck pixel density （779.03±125.79）, greater trochanter pixel density （526.22±127.93）, ward triangle pixel density （668.30±131.19）. There were significant differences between two groups （P0.05）. It is indicated that pelvis pixel density by DR technology can be used as one of the methods of measuring bone mineral density, and the operation is simple, having potential for application, avoiding second medical examination.