Institute of Computer Science, Jagiellonian University, ul. prof. Stanisława Łojasiewicza 6, 30-348 Kraków, Poland.
Comput Biol Med. 2013 Dec;43(12):2238-55. doi: 10.1016/j.compbiomed.2013.10.009. Epub 2013 Oct 26.
Gallbladder function is routinely assessed using ultrasonographic (USG) examinations. In clinical practice, doctors very often analyse the gallbladder shape when diagnosing selected disorders, e.g. if there are turns or folds of the gallbladder, so extracting its shape from USG images using supporting software can simplify a diagnosis that is often difficult to make. The paper describes two active contour models: the edge-based model and the region-based model making use of a morphological approach, both designed for extracting the gallbladder shape from USG images. The active contour models were applied to USG images without lesions and to those showing specific disease units, namely, anatomical changes like folds and turns of the gallbladder as well as polyps and gallstones. This paper also presents modifications of the edge-based model, such as the method for removing self-crossings and loops or the method of dampening the inflation force which moves nodes if they approach the edge being determined. The user is also able to add a fragment of the approximated edge beyond which neither active contour model will move if this edge is incomplete in the USG image. The modifications of the edge-based model presented here allow more precise results to be obtained when extracting the shape of the gallbladder from USG images than if the morphological model is used.
胆囊功能通常通过超声（USG）检查来评估。在临床实践中，医生在诊断某些疾病时经常会分析胆囊的形状，例如如果胆囊有转弯或褶皱，那么使用支持软件从 USG 图像中提取其形状可以简化通常难以做出的诊断。本文描述了两种主动轮廓模型：基于边缘的模型和基于区域的模型，均利用形态学方法设计，用于从 USG 图像中提取胆囊形状。主动轮廓模型应用于无病变的 USG 图像和显示特定疾病单元的图像，即胆囊的解剖学变化，如折叠和转弯以及息肉和胆结石。本文还介绍了基于边缘的模型的修改，例如去除自交叉和环的方法，或者在节点接近要确定的边缘时减弱使节点移动的膨胀力的方法。用户还可以添加超出逼近边缘的片段，如果 USG 图像中的边缘不完整，则两个主动轮廓模型都不会移动。与使用形态学模型相比，本文提出的基于边缘的模型的修改可以在从 USG 图像中提取胆囊形状时获得更精确的结果。
