MPEG-4 is a new standard for compressing and presenting many types of multimedia content, such as video, audio, and synthetic 2D and 3D graphics. New features include support for user interaction and flexible display of multiple video bitstreams. The basis of these new capabilities is object- based video coding, in which a video image is represented as a set of regions of interest, or video objects, that are coded independently. At the decoder, users decode, compose and manipulate video objects from one or more bitstreams in a single display. In this work, we examine the feasibility of using MPEG-4 for coding ultrasound sequences. In preliminary results, the compression performance of MPEG-4 was comparable to H.264 and a bit savings of at least 15 percent was possible when coding static objects as sprites. The flexible compositing capability of MPEG-4 was demonstrated by dividing an ultrasound machine's display into video objects and encoding each video object as a separate bitstream. Video objects form different bitstreams were decoded and composited on a single display using an MPEG-4 decoder to demonstrate side-by-side comparisons of ultrasound scans. Until now, these compositing capabilities were only available using proprietary PACS display systems. Using MPEG-4 to deliver ultrasound allows any MPEG-4- compliant decoder to perform these functions.