What pertinent positive radiographic findings are associated with psoriatic arthritis? (list eight)

1. Pencil-in-cup deformity of the distal interphalangeal or proximal interphalangeal joints due to central erosions (pathognomonic)
2. Fluffy periostitis
3. Ankylosis
4. Resorption of terminal tufts (acro-osteolysis)
5. Severe joint space narrowing or fusion (arthritis mutilans)
6. Sausage digits
7. Mouse ears (bone proliferation adjacent to intra-articular bare areas)
8. Asymmetric sacroiliitis (not shown in figure)