You may be able to use hdiutil in the Terminal?
For quick help & the manual (use arrows to navigate then hit q to exit the manual reader).
The examples are way down in the bottom of the manual.
in theory the following should do it… (taken from 10.6.8's hdiutil manual).
hdiutil create -type SPARSE -size 1g -fs HFS+ ~/Desktop/growableTo1g
There was an 'advanced gui' setting for Disk Utility, it may add the feature back search for 'defaults write disk utility' if the following doesn't help.