1. Psoriatic arthritis imaging
Dr Tazeen Ahmed
Consultant Rheumatologist
Croydon Health Services

2. Hands

3. More Hands
63 F

4. More Hands- closer

5. US hand

6. US Hand

7. MRI hands

8. Right hand sagital fat sat fluid sensitive sequence – marrow fat should be black: Seronegative fingers ring,middle and index – marrow fat should also be low signal but note whole bone of middle phalanges and distal phalanges are edematous not just the periarticular bone.

9. Left hand same pt seronegative.
T1 sequence - marrow should be white as fat is high T1 signal – note dark prox phalanx index finger.
Fat Sat sequence same hand: note bright prox phalanx of index finger because edematous

10. Psoriatic arthritis imaging
X-Ray reports can be misleading
Difficult to tell the difference between PsA and OA on imaging alone
US can distinguish from RA and also OA- but there are overlaps
MRI will show bony changes such as osteitis that are not seen on X-ray or US
NSAIDs will affect US changes, so please omit for a few days before the scan.