How determine if a photoshop elements 15 backup contains certain pictures before restoring

I was looking at my Photoshop Elements 15 organizer and noticed that 3 years of my folders were missing (2004 to 2006) from my catalog from 2003 to present. I did a lot of work on my catalog these past two weeks (when I did my last incremental backup) and would rather not restore from there if those folders were also missing then and I just didn't notice.  I have no idea how these folders actually disappeared and when I do a for specific photo files they don't appear.  All of these folders are still on my hard disk, so only deleted from photoshop.  
How do I open files in my backup to see if any of these missing photos are there before I restore and lose all the work that I have done?
Thank you for any assistance you can provide.