Patient Notes is a Bookem Premium feature. To reuse a document, image, table or chart that you'd like in your Notes, you can create a Note Form out of it.
Here's a video
Go to Forms / Note Forms
Click + Add , name your Note Form
Add a Field type called 'Diagram'
Save and close
You'll be able to access this note form in any Note you're making by clicking on the clipboard image on the top right of your Note.