口腔CT骨密度测量方法的设计与实现

发布时间：2018-10-22 12:08

【摘要】：随着人们生活水平的提高和人口的老龄化,骨质疏松症得到了广泛的关注,牙齿种植技术也得到了广泛的应用,在骨质疏松症的诊断和牙齿种植过程中骨密度测量是至关重要的。骨密度测量技术有多种,在实际应用中,无体模测量骨密度的方法简便,但不能排除肌肉和脂肪的影响,给测量结果带来了一定的误差,而且结果的可重复性比较差。目前,口腔CT在骨密度的测量中发挥着越来越重要的作用,本文基于口腔定量CT提出了一种体外定标的方法,即有体模测量骨密度方法。体模分为两种：液体体模和固体体模,由于固体体模制作工艺复杂且价格昂贵,本文研制了工艺简单,价格低廉的液体体模,为了验证液体体模的可行性,做了如下工作：(1)用口腔CT机扫描液体体模以验证它的均匀性,取扫描图像中的十层图像,进行对比分析,发现液体体模均匀性很好。(2)分别扫描液体体模和固体体模来验证它的线性度,取扫描图像中的十层图像,通过对比发现液体体模的拟合度要比固体体模的高,达到了0.9997。(3)同时扫描固体和液体体模以及质量控制体模,取扫描图像中的十层图像,通过比较测量结果,骨密度值差别在3～5之间变化,最大相对变化为2.91%。(4)液体体模多次测量,取扫描图像中的十层,从十层的结果比较可知,体模的重复性和稳定性很好,能保持在半年内。(5)液体体模和骨样本同时扫描,与骨样本的灰化值进行比较,尽管误差较大,但是线性相关性达到了0.9,说明骨密度能很好的反映骨矿物质的变化。为了验证口腔CT测量骨密度的准确性,采用东软研发的大型螺旋CT的测量结果作比较,口腔CT与大型螺旋CT测量误差在0.2%内,可以忽略不计。为了将这种方法很好地应用于临床检验,根据设计流程和实现原理,在定量CT上成功开发一个有体模骨密度测量软件。
[Abstract]:With the improvement of people's living standard and the aging of population, osteoporosis has been paid more and more attention, and dental implant technology has been widely used. Bone mineral density measurement is crucial in the diagnosis of osteoporosis and dental implants. There are many kinds of bone mineral density measurement techniques. In practical application, the method of measuring bone mineral density without phantom is simple, but the influence of muscle and fat can not be excluded, which brings some errors to the measurement results, and the repeatability of the results is poor. At present, oral CT plays a more and more important role in the measurement of bone mineral density (BMD). Based on oral quantitative CT, a method of in vitro calibration is proposed in this paper. There are two kinds of phantom: liquid model and solid model. Because of the complexity and high cost of making solid model, a simple and inexpensive liquid model is developed in this paper, in order to verify the feasibility of liquid body mold. The following works have been done: (1) the liquid model is scanned by oral CT machine to verify its uniformity. Ten layers of images are taken from the scanning image, and the results are compared and analyzed. It is found that the uniformity of the liquid model is very good. (2) the linearity of the liquid model is verified by scanning the liquid model and the solid model, and the fitting degree of the liquid model is higher than that of the solid model by comparing the ten layers of images in the scanning image. 0.9997. (3) scanning solid and liquid models and quality control phantom at the same time, taking ten layers of images from the scanning image, the difference of bone mineral density is between 3 and 5, and the maximum relative change is 2.91. (4) the liquid phantom is measured many times. From the comparison of the results of the ten layers of scanning images, we can see that the reproducibility and stability of the phantom are very good and can be maintained within half a year. (5) the liquid phantom and the bone sample are scanned simultaneously, which is compared with the ashing value of the bone sample, although the error is great. But the linear correlation reached 0.9, indicating that bone mineral density can well reflect the change of bone mineral. In order to verify the accuracy of bone mineral density (BMD) measured by oral CT, the measurement results of large spiral CT developed by Neussup were compared. The measurement error between oral CT and large spiral CT was within 0.2%, which could be ignored. In order to apply this method to clinical test, according to the design flow and realization principle, a volume model bone mineral density measurement software was successfully developed on quantitative CT.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R816.98

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