Noninvasive quantitative assessment of synovial pannus angiogenesis by contrast-enhanced gray-scale sonography in antigen-induced arthritis in rabbits.

RATIONALE AND

OBJECTIVES

The aim of this study was to evaluate the value of contrast-enhanced gray-scale sonography in quantitative assessment of synovial pannus angiogenesis in antigen-induced arthritis in rabbits.

MATERIALS AND

METHODS

Twenty-four adult New Zealand White rabbits were divided into two groups. Inflammatory arthritis was induced by intra-articular injection of ovalbumin into right knee joints with 4 mg in low-dose group (LD, n = 12) and 8 mg in high-dose group (HD, n = 12). The left side of the knee on each rabbit was used as normal control. Contrast-enhanced gray-scale sonography with time intensity curve (TIC) was performed on the synovia of suprapatellar bursa and posterior capsules 4 weeks after the injection. Immunohistochemical examinations of synovia were applied to assess the microvessel density and the expression of vascular endothelial growth factor. Correlation analysis between sonographic and immunohistochemical findings was performed.

RESULTS

Contrast-enhanced gray-scale sonography of all right knees demonstrated intra-articular hypoechoic lesions with enhanced blood flow and no abnormal findings on all left knees. Parameters of TIC, including ascending curve (A), derived peak intensity (DPI), and area under curve (AUC) on arthritis joints were significantly higher in HD group compared to LD group (P < .05). Positive correlation was found between immunohistochemical findings and parameters of A, DPI, and AUC (P < .05). However, no correlation was found between other parameters (slope of descending rate, time to peak, time to rise, and initial intensity) and immunohistochemical findings.

CONCLUSIONS

Contrast-enhanced gray-scale sonography with TIC measurement could provide reliable method for noninvasive quantitative assessment of synovial pannus angiogenesis of arthritis in clinical settings.