[aperson30]

What

MRI window presets. MRI has no fixed units, so its windows come from the scan's own intensity distribution. The list is now Auto, Low contrast, Medium contrast, High contrast and Full range. Low, Medium and High follow the usual PACS automatic presets: they drop 1%, 5% and 10% of the foreground voxels from each end of the range, so a larger trim gives a narrower window and more contrast. This replaces the old "High contrast" window, which only raised the lower bound. ScanAnalysis gains the extra foreground percentiles these need. CT presets are unchanged.

Invert. The View menu gets an Invert toggle (state shown in place like Hover identify and Reference lines; no controls moved). It flips the grayscale of every pane through Cornerstone's invert property and is re-applied when the viewports are rebuilt. It is not saved between visits and applies to CT as well as MRI.

Tests

• scanModality.test.ts: preset names, trim edges and ordering.
• viewer.smoke.test.tsx: the Invert menu item toggles and shows its state.
• Ablations: changing the High contrast trim fails the preset tests; making the Invert click a no-op fails the smoke test.
• Checked in a real browser (Edge, local dev server) with a synthetic MRI NIfTI: detected as MRI, the five presets are listed, and Invert flips all three panes.
• Locally: typecheck, ESLint (0 errors) and the affected vitest files pass. Full CI not run locally.

Not verified / not changed

• Not checked on a real clinical MRI or a DICOM MRI series, only the synthetic scan.
• The compare viewer does not get Invert in this PR.
• No "use the window stored in the file" preset and no user-saved presets yet.
• No access-policy or backend change.