The macOS desktop app
What the packaged app does that the browser build cannot.
The packaged macOS app is the same workspace as the browser build, plus the system integration a browser tab cannot have. Everything below is desktop-only.
Opening files from the system
.dcm, .dicom, and .dic files are registered to the app, so double-clicking one in Finder — or using Open With — opens it here. The same rules apply as in-app: with no study loaded the file opens as a new study; with one loaded it is added to the current session.
Recently opened studies appear in File → Open Recent and in the Dock icon’s right-click menu. When you open a folder, the folder is what gets recorded, not the slices inside it.
The native menu bar
Standard macOS menus with real accelerators — ⌘O open, ⌘⇧O open folder, ⌘S export, ⌘P print, ⌘W close study, ⌘Z / ⌘⇧Z undo and redo. Menu checkmarks and enabled states follow the app: the current mode and layout are ticked, and items that would do nothing are greyed out.
Handbook in its own window
Help → Open Handbook (⌘?) opens this handbook as a separate, resizable window instead of a modal, so it can sit on a second display while you work.
Sharing and printing
Export → Share Active Image… hands the current frame to the macOS share sheet — see Share active image. File → Print… opens the same resolution chooser as the top bar, described in Print diagnostic frame.
What the app does not do with your data
The app registers no Spotlight importer, no Quick Look generator, and no metadata importer for .dcm files. macOS lets a bundle install these to read file contents into the system-wide index or thumbnail cache; this one does not, so Patient Name, MRN, and Date of Birth never leave the app’s own process boundary through that route. In-app search (⌘K) stays inside the app’s local history and never touches Spotlight.
The one file the app writes on its own is the PNG behind the share sheet. It goes to the app’s private cache and is cleared when the study is closed or replaced, and again at app start.
Note Window size, position, and appearance (Dark / Light / System) are restored across launches. Most UI text is not selectable — the chrome is meant to read as a cockpit, not a web document, so a stray drag cannot select across controls. Text fields, this handbook, and the DICOM scan review remain selectable.