multimedia data storage issue

Hi,
I'm a student of Gdansk University of Technology. Now I'm getting prepare to write my M.A. thesis. The topic of my work is "An interface in
multimedia databases in radiology". One of the main tasks which I would like to do is to investigate how different database vendors store different
multimedia data types. It includes data types like signals ( 1 and 2 - dimensional ), images, video sequences or 3d-objects. I'm searching for any kind of
product documentation of leading database vendors (Oracle, PostgreSQL, MySql, Sybase, and others...) which concern on multimedia data storage problem (exactly: what data
types they use to store multimedia data, what kind of data model they use to describe that data, what is the way of access to the data )

Thanks a lot for any help!

best regards
Dariusz Dzingielewski
Gdansk University of Technology
Informatics in Medicine