Magnetic resonance imaging of psoriatic arthritis: insight from traditional and three-dimensional analysis.

The magnetic resonance imaging (MRI) findings in psoriatic arthritis (PsA) are the same and at the same time different from those seen in other inflammatory arthritides. Synovial hypertrophy is seen on MRI in all arthritides. However, the location and extent of bone marrow edema in PsA is different from those seen in rheumatoid arthritis (RA) and osteoarthritis. Progression studies in PsA are hard to justify. However, treatment monitoring studies have given insight into the pattern of progression of the MRI findings and information regarding the mechanism of the effect of the drugs used for treatment. Three-dimensional image analysis tools provide volumetric information and information regarding the spatial and temporal relationship between different MRI findings. The three-dimensional perfusion image analysis tool, which is used to evaluate the effect of antiangiogenic drugs in cancer treatment, can provide information regarding the disease mechanism when used in disease monitoring studies.