Corrupt disk image after power failure


After a power failure (which shut down my iMac) two very important encrypted disk images (about 20 GB each), which were mounted at that incident, failed to mount again. I got this message instead:

The following disk images have failed to mount: Reason "corrupt image".

After that I tried to do a fsck-check in the Terminal (I don't know very much about the command line but I were able to check this out). Outcome:

BAD SUPER BLOCK: MAGIC NUMBER WRONG ioctl (GCINFO): Inappropriate ioctl for device fsck: /Users/ral/Desktop/IT Kopie.sparseimage: can't read disk label.

I'm really desperate! Because I don't have a backup of the data (I was actually on the way to do backups when the power failure occurred!). What can I do? Is there a way to save my data? There has to be one! Perhaps with a disk repair app or something like that (I have already tried some, but failed (the volumes have to be mounted...)?

BTW shouldn't the "journaled" feature of the file system on the DMG prevent this from happening? I really need your help!