How to Check Creation/Change data for PO Service Line item

Hi, I was wondering what field(s) from what table(s) I would have to check if I wanted a report to look for the creation or chnaged date of a specific service item in a PO?

Currently it is using the EKPO-AEDAT field to check if a PO line item has been changed, but I would like to narrow it down to just some service line items instead of capturing all the service lines in a recently changed PO line item.

Thank you very much in advance for the advice!