Department of Computer Science, University of Pennsylvania, Philadelphia, PA 19104.
IEEE Trans Pattern Anal Mach Intell. 1986 Feb;8(2):188-99. doi: 10.1109/tpami.1986.4767772.
This paper details the design and implementation of ANGY, a rule-based expert system in the domain of medical image processing. Given a subtracted digital angiogram of the chest, ANGY identifies and isolates the coronary vessels, while ignoring any nonvessel structures which may have arisen from noise, variations in background contrast, imperfect subtraction, and irrelevent anatomical detail. The overall system is modularized into three stages: the preprocessing stage and the two stages embodied in the expert itself. In the preprocessing stage, low-level image processing routines written in C are used to create a segmented representation of the input image. These routines are applied sequentially. The expert system is rule-based and is written in OPS5 and LISP. It is separated into two stages: The low-level image processing stage embodies a domain-independent knowledge of segmentation, grouping, and shape analysis. Working with both edges and regions, it determines such relations as parallel and adjacent and attempts to refine the segmentation begun by the preprocessing. The high-level medical stage embodies a domain-dependent knowledge of cardiac anatomy and physiology. Applying this knowledge to the objects and relations determined in the preceding two stages, it identifies those objects which are vessels and eliminates all others.
本文详细介绍了 ANGY 的设计和实现，ANGY 是一个基于规则的医学图像处理领域的专家系统。给定一张经过减影处理的胸部数字血管造影图像，ANGY 可以识别并分离出冠状动脉，同时忽略可能由于噪声、背景对比度变化、减影不完全和不相关的解剖细节而产生的任何非血管结构。整个系统分为三个阶段：预处理阶段和专家系统自身的两个阶段。在预处理阶段，使用 C 语言编写的低级图像处理例程来创建输入图像的分割表示。这些例程是顺序应用的。专家系统是基于规则的，用 OPS5 和 LISP 编写。它分为两个阶段：低级图像处理阶段体现了分割、分组和形状分析的领域独立知识。它既可以处理边缘也可以处理区域，确定平行和相邻等关系，并尝试细化预处理开始的分割。高级医学阶段体现了心脏解剖和生理学的领域相关知识。将这些知识应用于前两个阶段确定的对象和关系，可以识别出那些是血管的对象，并消除所有其他对象。
