Validation

Diff between two studies/files

Compare two files or studies and highlight every differing tag and pixel.

Problem

You have two versions of a DICOM file — the original and an anonymized copy, or a before-and-after edit — and you need to see exactly which tags changed, what the old and new values are, and whether any unexpected modifications occurred. A visual diff table shows side-by-side comparisons for every tag that differs between the two instances.

Steps

Load multiple files (⌘O) — e.g. test.dcm and sample-siemens.dcm.
Switch to the Files tab in the right rail and click Compare.
Select the A (old) instance — choose #1 · test.dcm from the dropdown.
Select the B (new) instance — choose #1 · sample-siemens.dcm from the dropdown.
Review the diff table — the modal displays rows for every tag that differs between the two files. Each row shows the tag ID, tag name, value in A, and value in B.

Expected Result

The Compare modal opens with A/B instance selection dropdowns.
After selecting both instances, a diff table renders showing all differing tags.
The diff row count is greater than zero when comparing different files.
Tags that are identical between A and B are not shown (only differences are displayed).