tlv,
Most of my labs are direct HL7 imported into AC the rest are e-faxed into Updox as a PDF. Very few are scanned in, usually those brought in by patient.
In Updox one can edit, such as print time and date stamp, actual electronic signature, type letter/numbers, erase, free hand write etc. any of the documents. If outgoing from Updox, however, the changes will not be kept in AC, if ingoing to inbox into AC those edits are saved.