of PACS browser with the rest of the network Cluster Controller

Despite over a decade of research and development, medical image compression has not yet been widely implemented on clinical picture archiving and communication systems (PACS). We have developed a prototype interface which incorporates both lossless and lossy compression into a browsing system that enables the efficient use of network and storage resources. Such a system allows an user to quickly browse through a large set of image icons created from lossy compression and selectively retrieve the original images for diagnosis from the optical disk that contains losslessly compressed image data. For lossless compression, we implemented modality specific techniques which combines preprocessing, adaptive prediction and entropy coding, giving a compression improvement of 20% over JPEG predictors. The lossy compression algorithm consists of subsampling followed by wavelet transform coding and achieves compressed CR images of sufficient quality for browsing at a compression ratio of about 2000:1.