We have a system whereby they deploy windows 7 to a tablet type device using a bootable USB thumb drive and an ImageX image.  After several technical errors where the wrong image was deployed due to someone using old USB thumb drive I've been tasked with finding a way to do it without the bootable usb drive.   (preface - I've never used ImageX before)

Is there a way to extract the image given the scenario that I have a Windows 7 PC and have a USB drive dock whereby I can put a blank disk in, extract the imageX image to that disk, remove that disk and put it into the tablet and do the next disk/tablet?

Why aren't you at least using MDT -- The Microsoft Deployment Toolkit? It's a widely used and free toolkit for deploying Windows.

Also note, this is System Center Configuration Manager forum; ConfigMgr also contains a feature set similar to MDT.