Acronis True Image is compatible with BitLocker hence can back up and restore partitions encrypted by BitLocker.
Install Acronis True Image on your computer and configure a backup task to back up encrypted disks. You need to unlock the disk (use Suspend protection option for that) before backing up. You cannot back up encrypted disks in Acronis bootable media.
To restore encrypted disks, start your computer with Acronis bootable media and configure a recovery task. You need to reactivate encryption after recovery. You cannot restore encrypted disks using Acronis True Image in Windows.