Report to identify responses that had attachments

I was looking to build a report to identify agent responses from incidents that had attachments added to them. I thought it would be easy as the thread control displays the attachments included in response and whether they were sent or not (refer screenshot for example).

But when I am trying to build a report I don't see the joins available from the threads table allowing this. I also tried joins available from transactions table for transaction type = Response Sent. But no luck. Any insight/guidance on this will be appreciated.

Regards,

Makarand.