How to update imported pictures

[Schwabe]

I have been using Microsoft Visio in my iPhone/Android app design workflow.   I use it to import a series of UI snapshots and arrange them to illustrate a sequence of user actions.

Visio is nice because it's easy to do this kind of layout and I can later convert it to PDF to share with developers.

However, it gets difficult to manage with a high number of screens because everytime an update is made to the source graphic I have to re-import it into Viso to reflect the change.    

Isn't there a way to ensure pictures are automatically updated when the source file is updated?

(Visio 2010)