I got some seismic data into MeVisCalc by starting with a 3D migrated data volume, running the seismicunix (SU) program sustrip to create raw 32-bit binary data. By double clicking on the ImgLoad icon a parameter window pops up and you can enter the dimensions and type of your data. Some experimentation is needed since seismic data is column-major and medical software expects row-major data that comes naturally from medical scanning devices. In other words, your data is likely to end up sideways in MeVisCalc, but that is no problem since the 3D viewer (Modules>Visualization>3DVeiwers>View3D) is an openGL type of interactive display and you can easily spin the data around to the orientation you want.
At first it seems a lot of trouble to plot some data. But after playing with it a bit, I can see it is a middle ground between writing code and a menu based application like, say, ImageJ. Once you have set up the flow and parameters in MeVisCalc, it is very easy to duplicate the process on new data as opposed to large number of menu operations. But ImageJ has a macro recorder that may play a similar role.
The medical imaging demos in MeVisCalc are impressive (VTK and other graphics engines are build in). Here is a shot of a little program I built to display some 3D GoM data....