1. Window A is the primary reference (an axial slice, or a previously acquired slice). Drag the line to set its position and angle — this defines an intermediate plane.
2. Window B automatically shows that intermediate plane as its reference. Drag the line in B to plan the final slice orientation on top of it.
3. Window C shows the single resulting slice, computed from both plans. When you are happy with it, tap Acquire Slice to save it to the Acquired list.
4. Drag a line body to move it; drag an end handle to rotate. Works with mouse and touch.
5. Pick a Plane type to label and colour the result. Switch Window A's reference between Axial and Acquired in the bottom bar; the axial slider appears only in axial mode.
6. In the Acquired list, tap Use as Window A ref to load a saved slice back into Window A — enabling chained multi-oblique planning (e.g. plan a 4-chamber from axial, then a short axis from that 4-chamber).
7. Window / Level is shared across all windows; Auto restores automatic windowing. Reset clears acquired slices and returns to the axial middle slice.

Educational and training tool only — not intended for diagnostic use or clinical decision-making.