Chan F H, So A T, Kung A W, Lam F K, Yip H C
Department of Electrical and Electronic Engineering, University of Hong Kong, Hong Kong.
Biomed Mater Eng. 1995;5(3):169-83.
A computerised thermal imaging system for thyroid diagnosis was developed by the authors and it was discovered that the rate of changes of temperature, rather than the absolute values, associated with a sequence of thermograms could help the medical doctors to identify clinical disorders. In order to further enhance the diagnostic capabilities and speed, a new method for medical thermogram analysis has been developed that compresses a sequence of thermograms into one thermogram while retaining the important information such as the geometrical patterns of the objects and the rate of temperature changes of each pixel within the images. As motion artifacts are unavoidable when a patient undergoes minutes of thermogram recording, direct comparison between images is deemed impossible. A high speed image matching algorithm has been developed to provide an absolute geometrical foundation for pixel-to-pixel comparison. The rate of change of temperature of a particular pixel along the sequence is represented by one single parameter after a process of temperature integration which can then be converted into a corresponding gray level for display. The resultant compressed thermogram can give a clear distinction between problem areas and normal ones. Although our emphasis is on thyroid diagnosis, it is anticipated that this new technique can be applicable to other areas of a human body.
作者开发了一种用于甲状腺诊断的计算机化热成像系统，并且发现与一系列热成像图相关的温度变化率而非绝对值，能够帮助医生识别临床病症。为了进一步提高诊断能力和速度，已开发出一种新的医学热成像图分析方法，该方法将一系列热成像图压缩成一幅热成像图，同时保留诸如物体的几何图案以及图像内每个像素的温度变化率等重要信息。由于患者在进行数分钟的热成像图记录时运动伪影不可避免，因此图像之间的直接比较被认为是不可能的。已开发出一种高速图像匹配算法，为逐像素比较提供绝对的几何基础。经过温度积分过程后，特定像素沿序列的温度变化率由一个单一参数表示，然后可将其转换为相应的灰度级进行显示。所得的压缩热成像图能够清晰地区分问题区域和正常区域。尽管我们重点关注甲状腺诊断，但预计这项新技术可应用于人体的其他部位。
