Coronal–Axial Plane Projection (CORO / LT / SL)

Carpal bone instability occurs when the ligaments holding the scaphoid, lunate, and triquetrum together (the scapholunate (SL) and lunotriquetral (LT) ligaments) are torn, allowing these bones to shift out of alignment during wrist motion. Assessing this instability from a single fixed imaging plane is challenging, since the true 3D carpal motion may not be fully captured by any one 2D slice, raising the question of whether measurements taken in different planes actually agree with one another.

This video shows the coronal (CORO) view with the intersection lines of the two oblique axial planes (LT and SL) overlaid, alongside the LT and SL axial views with the coronal plane's intersection line overlaid in return. These intersection lines, derived directly from the DICOM geometry, mark where each plane crosses the others, allowing the same inter-bone gap to be located and compared across acquisitions. This cross-plane projection is what enables the reliability of the coronal and axial measurements to be assessed against each other.