Image Integrity

I believe this is the appropriate forum for this question...
As part of an image backup process I view the image by mounting it as a vhd.
The first mount requires the read only box to be unchecked (obviously allowing the image to be written to). Otherwise the disk appears as unallocated.
Can I jeopardise the integrity of the image by doing this?

No, you can't unless you do something to it, but you obviously need to be warned - if you change anything in it, your backup gets changed, with consequences I can't predict. The easiest thing to do if you have the storage space is to copy the .vhd to another location and mount it from there, so your backup can remain unperturbed while you browse your image.