Volume visualization is a method of extracting meaningful information from volume data using interactive graphics and imaging

and it is concerned with volume data representation

modeling

manipulation

and rendering. Medical visualization

one of the most successful scientific visualization research and fields

is heading from diagnosis assistance toward treatment assistance. The aim of volume visualization in medicine is to create accurate realistic views of objects from medical data. The process of volume visualization technology includes data caching

model creating

data mapping

rendering and so on. There are two methods in volume visualization: surface rendering and volume rendering. The intermediate surface representation is used in surface rendering technique. The surface information is fast represented

but the inner information is not displayed. Volume data are directly represented in volume rendering technique

so the inner information can be displayed. The primary illumination models in medical visualization and the basic ideas of various algorithms in image space and object space of volume rendering technique are introduced. The methods for accelerating processing and improving image quality at present are discussed in detail. Some experimental data and results are presented in the end.