Ghosting to create images and clone drives

I am trying to ghost a drive with three partition, in which the OS drive is the middle partition. I have tried to just image the OS partition and I have tried to image the drive; however, the image file is just not large enough for the disk to be a complete image and neither is the partition image. I have also tried a disk to image copy to an external USB and I am unable to see the hard drive to image. Any ideas please? Thanks, JR