显微CT的研究及应用的初步评述

近五年来在国内外显微CT的研究和应用，得到了很大的发展；微观病理显微诊断的空间分辨为微米数量级。目前医学CT影像的空间分辨率已达到0.35mm，已能满足宏观病理学诊断的要求。如何医学CT的空间分辨率再提高到微米水平，即可清晰显示细胞和组织的微细结构，从而满足现代医学临床病理诊断金标准的要求。目前工业CT（ICT）的空间分辨率已达到5－20微米，从而为提高医学CT的空间分辨率提供技术依据。本文引述用工业微焦点CT机首次对小动物组织进行显微成像的结果：提出应用微焦点X线源，以及采用钨酸镉集成电路CCD检测技术，进一步缩小检测元器件探头的尺寸和增加检测器探头的数目，可以提高医学CT的空间分辨率；应用电子束快速扫描技术，可以提高医学CT的时间分辨率，达到动态的水平；应用双能X线束扫描技术，可以进一步提高密度分辨率，如果未来医学CT的空间分辨率达到微米级（显微CT），时间分辨率达到毫秒级（动态CT），密度分辨率能观察到神经细胞有兴奋时，胞内钙离子浓度的瞬态上升1000倍，即成为显微动态和功能CT，就可以观测人脑神经元在不同功能状态下的动态兴奋和时空编码过程，对进一步研究人脑的记忆和思维认知过程有重要意义。

A Preliminary Review of Micro-CT and its Applications

Since 1995, Industrial CT has gained a great progress to improve its spatial and temporal resolution1], the Micro-CT getting large progress in United States, Europe and China; Prof. Chen Weichang et al. develop the research on Micro-CT and its method, they using the high resolution ICT scanner to image rat's organs2]. Dr. Ge Wang, PhD, Director of the Micro-CT Lab, USA, provides reviews in some journal and Internet web,and cooperate with some university and CT-scanner company, to device micro-CT scanner. There are 5-company in United States and Europe, provide Micro-CT scanner with high resolution(5-50μm ). The resolution of the microscopic diagnosis is about 5-50μm. If the spatial resolution of medical CT can increase to 2～10 micrometer domain, then cells and tissues can be visualized and then the microscopic pathological diagnosis can be made by using the medical micro CT(μCT). μCT and 3D stereological will promote operation technique to a new period. It is obvious that the micro CT will give a great impact on the clinical medicine in the 21 century.