If the files were stored in a directory, then you can simply use a recovery solution, and luckily, there are plenty available both paid and free.
As a free solution, I recommend Recuva since it's small and efficient when it comes to file recovery.
Download the application through the page below and then initiate the scan. Point the scanner to the directory where the xrays were previously stored and enable Deep Scan on the next screen. Once you find the files, right click them and choose Recover, but make sure to save them on another partition.