Beware of calling dorsal intercalated segment instability (DISI) on MRI alone as relationships vary with wrist position, and standard measurements are based on lateral wrist radiographs. 

The thick dorsal portion of the scapholunate ligament is the primary structure balancing the forces across the scapholuate joint, preventing posterior rotary tilt of the lunate. If a DISI pattern exists, this structure is most likely not intact. In contrast, the thick volar lunotriquetral ligament resists volar rotary turn of the lunate, which if ruptured would increase the capitolunate angle in the reverse direction as is seen here (i.e. VISI).