Can I use regular disk imaging utilities with encrypted volumes?

Yes, you can. 

Please note that if you create the disk image when the volume is dismounted, you will get the encrypted image. 

If the volume was mounted, the image will be unencrypted. So for system volume - you always get unencrypted images.
If you restore from such an image, you will have to restore MBR sector manually.
It is recommended to install disk imaging software BEFORE encrypting the system volume.