CE-MRI phenotyping of collapsed vs. expanding PLN and asymmetric knee arthritis in TNF-Tg mice. TNF-Tg mice (n = 10; 20 legs) with ankle arthritis were monitored by CE-MRI to phenotype their PLN as expanding or collapsed. The quantitative data are presented in Table 1. 2D CE-MRI (A-D), and 3D reconstructed volumes (E-H), of the left (A, B, E, F) and right (C, D, G, H) legs of a representative TNF-Tg mouse with asymmetric arthritis are presented to illustrate the phenotypic differences between collapsed PLN (A, E), which are smaller and have limited contrast enhancement vs. expanding PLN (C, G), which are larger and have saturated contrast enhancement throughout most of the node. The asymmetric arthritic phenotype in this animal is also apparent from the contrast enhancing pannus tissue that surrounds the femoral chondyles in only one knee (red arrows in B), and the larger synovial volume 5.6 mm3 (F) vs. 3.8 mm3 (H).