Abstract
Objective: To assess the significance of power doppler ultrasonography (PDUS) in the evaluation of synovial lesion of the knee joint by comparing the PDUS findings with site-matched histopathological findings.
Methods: We studied 23 patients who were undergoing arthroplasty of the knee joint because of rheumatoid arthritis (RA) or osteoarthritis (OA). Predetermined sites of the knee joint were examined with US before arthroplasty. Synovitis was classified semiquantitatively with grey scale (GS) and PDUS findings. Synovial tissues were obtained during arthroplasty from the corresponding sites evaluated by the US. Histopathology of the synovial tissue was evaluated by haematoxylin and eosin staining and immunohistochemical staining with factor VIII.
Results:. We compared imaging findings of preoperative PDUS with histopathological findings of the synovial specimens. We found that the PDUS findings were mostly correlated with each histopathological grade of synovitis and the vascularity showed the highest correlation with the PDUS findings as expected. However, the site-matched comparison indicated that the blood vessels were not apparently detected by the PDUS. Thus, the sensitivity and specificity of PDUS findings for histopathological vascularity were 91% and 58%, respectively.
Conclusion: We found that the PDUS findings were mostly correlated with each histopathological score of synovitis with highest correlation to vascularity. However, the site-matched comparison indicated that the blood vessels without inflammatory cell infiltrates were not apparently detected by the PDUS.
