Yes it is and there are lots of ways of doing this.
Ephesoft is a place to start looking, but you could integrate any scanning software with Alfresco fairly readily.
The way you do it (in summary) is to implement your scanning and produce document images and metadata (standard stuff) then upload the documents and metadata into Alfresco (CMIS provides an API for this as does the REST API).
This makes it sound trivial which it definately is not, but it can be done, has been done and does work.
Bob Johnson