Content based image retrieval in PACS

Instead of search byKeywordsor annotations written by physicians,content based on image retrieval(CBIR)takes the image content and search the image database.This is what needed in real-life PACS system.Some CBIR algorithms are descibed,their principles and implementation are introduced.Time requirement and searching results are presented.The experimental results show that the symmetric relative entropy gives the best result and is combined into PACS system.