The presentation of data from medically imaged volumes

The past twenty years have seen a number of rapid advances in medical imaging technology. Many of the imaging systems produce volume data either as serial slices or as data points gathered from within a global 3D space. Whilst the imaging technology may have evolved rapidly, the ability to extract objective and quantitative information from the data has advanced much less. One clearly defined need is an effective way of representing 3D volumes and efficiently interacting with the images thereby generated. A general approach to the display of 3D data involves the identification of external of internal surfaces and structures, followed by a visualisation model. One can either segment the data to provide a surface for display or use some parameter of the data itself, such as opacity, to visualise structure. The two common techniques are surface modelling and voxel methods. The authors review the techniques in use and identify some of the current clinical applications