Problems with spherical coordinates display

Hi

my name is Dário Passos and I'm currently working in simulations of solar convection.
I have a matrix of 128x64x47 (x,y,z) that corresponds to latitude x longitude x radius (basically a shell corresponding to the solar convection zone).
I'm using IDL 7 to transform my data into an .vdf file so I can plot it in Vapor.
In the IDL routine, I use:

mfd = vdf_create(dim, num_levels)

to create the vdf file in spherical geometry. Following the examples I found online I also include the keywords:

vdf_setcoordtype, mfd, 'spherical'
periodic=[1,1,0]
vdf_setperiodic, mfd, periodic
extents = [-174.375,-84.375,0.65,174.375,84.375,0.96]
vdf_setextents, mfd, extents

The problem that I'm having is that when I import the data into VAPOR 2.3.0 (running in a Windows 7 PC), the REGION panel does not displays my coordinates in Lat, Long, Rad like in the online examples. It shows an X, Y, Z coordinate system. Therefore I cannot select just half a sphere for example. If I change the X, Y,Z selection slides I only get selection restricted to radius. So this hints that the program is somehow doing the sqrt(x^2 + y^2 + z^2) to constrain the radius.
Do you have any idea if I have to define anything else while producing the VDF file or configure something specifically for spherical coords. in Vapor in order to obtain the REGION selection sliders in Lat, Lon, Rad?

Thanks in advance.
Dário