Measurement of Temperature Distribution in Phantom Body by an Ultrasonic CT Method

超声CT法测量人体模型温度分布

基本信息

批准号：
07650273
负责人：
NAWATA Yutaka
金额：
$ 1.66万
依托单位：
Yatsushiro National College of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650273/
关键词：
Measurement Ultrasonic Wave Heat Transfer Computed Tomography Temperature Distribution Living Body

项目摘要

It has been getting importance to measure the interior temperature in the body since hyperthermia appeared in treatment of cancer. In this treatment, it is important to hold the temperature of tumor over 42.5ﾟc to avoid the heat damage of normal tissue. We anticipate a technology measuring indirectly the interior temperature distribution of the arbitrary transverse section in the body and displying the image for monitoring.In this paper, An ultrasonic CT (Computed tomography) method is researched for measuring indirectly the interior temperature distribution from a series of sound projections that are taken at several different orientations relative to a phantom body. Ultrasonic CT is mainly one of the methods getting the transverse image of the body as the same as X-ray CT.But it has the advantage of simpler instrument because it doesn't have the radiation injury like X-ray CT.We can obtain the sound speed distribution within the object by measuring the arrival time of sound wave with … More ultrasonic CT.The purpose of this study is to develop the method measuring indirectly the interior temperature distribution of an object from the difference of sound speed between heating and non-heating, using the characteristics the sound speed depends on the temperature.First, we compare three reconstruction algorithms to minimize a number of required projections. Next, we make an experiment about the dependence of temperature on sound speed in water and get a relation between the temperature and the sound speed in water. Then, phantoms made of agar are placed in a water bath, and a series of sound projections is measured when a pair of ultrasonic detectors are both translated and rotated. We can obtain the temperature distribution in phantom with accuracy 0.1ﾟc by subtracting the sound distribution when non-heating from one when heating. The structure differences of watery tissue like blood, musculature, and the viscera do not effect on the measurement of the temperature distribution, because it is deleted by subtracting the sound speed when non-heating from the sound speed when heating.Lastly, We make an experiment in which there is a bone crossing the transverse section of the ultrasonic measurement. When bone or gas is in the area of measurement, the projections include a data missing part. As a result of the experiment, we could obtain approximately the reconstructed image by the modification of the projections, and the temperature distribution, too, if the missing part is small. But we can not calculate precisely the temperature distribution, if the missing part is large. Less

由于高温出现在癌症治疗中以来，测量体内的内部温度一直很重要。在这种治疗中，重要的是要在42.5 c c上保持肿瘤温度，以避免正常组织的热损伤。我们预期一项技术，可以间接测量身体中任意横截面的内部温度分布并将图像分配给监视。在本文中，研究了一种超声波（计算机断层扫描）方法，用于间接测量来自一系列声音项目的内部温度分布，这些声音在相对于凤凰体相对于几种不同方向采取的多种方向。超声CT主要是获得身体横向图像与X射线CT相同的方法之一，但它具有更简单的仪器的优势，因为它没有X射线ct的辐射损伤，我们可以通过测量声音的到达来测量该研究的散热范围，从而在方法中得出更多的超声范围。不加热，使用特征，音速取决于温度。首先，我们比较三种重建算法以最大程度地减少许多必需的项目。接下来，我们进行了一个实验，涉及温度对水的声速的依赖性，并在水中的温度和声速之间建立关系。然后，将琼脂制成的幻影放在水浴中，当一对超声检测器都被翻译和旋转时，将测量一系列声音项目。我们可以通过在加热时从一个不加热时减去声音分布来获得幻影中的温度分布。水组织（如血液，肌肉组织和内脏）的结构差异不会影响温度分布的测量，因为在加热时从不加热的声速中减去声速来删除它。当骨头或气体处于测量区域时，投影包括数据丢失。由于实验的结果，如果缺失部分很小，我们也可以通过修改投影和温度分布获得大约重建的图像。但是，如果缺失部分很大，我们将无法精确计算温度分布。较少的