Power Doppler sonography in the evaluation and follow-up of knee involvement in patients with juvenile idiopathic arthritis

Summary

Introduction This study was undertaken to evaluate the role of ultrasound (US), conventional color (CD) and power Doppler (PD) in the detection and quantification of inflammatory signs of the knee in children with juvenile idiopathic arthritis (JIA) and to correlate these findings with patient history, clinical, laboratory and radiological findings. Patients and methods Thirty patients with JIA who had clinical signs of knee involvement as well as 15 healthy children as a control group where subjected to full clinical examination and laboratory investigations on the same day of US examination. The knee joints were evaluated with plain radiography, US, and color Doppler in 13 patients, while the remaining 17 were assessed with power Doppler. Fourteen patients were subjected to follow-up assessment. Results A highly significant difference in synovial thickening and cartilage thickness detected by US between JIA affected knees and those of controls (p<0.0001). Knee effusion was demonstrated in 93% of patients. Synovial vessles were detected by Doppler in 76.7% of patients. A significant correlation was detected between the degree of vascularity detected by PD and knee score (p<0.05), and JAFAR score (P<0.05). On comparing the findings of the follow-up with those of the initial examination, a significant positive correlation was detected between the differences in the knee score and those in synovial thickness (p<0.05), and with the vascularity scale detected by PD (p<0.05). Conclusion This study suggests the Doppler sonography as a non-invasive, low-cost, and readily available tool for the evaluation and follow-up of articular involvement in knees of JIA patients.