To the Editor:
We thank Dr. Johannes Roth for his comments1 on our recent publication2. Dr. Roth raises several important points. The first is that for a Doppler signal to be considered abnormal it must exist within thickened synovium. This is based on adult studies and a recent consensus conference defining ultrasound (US) requirements for the pediatric population3. Physiologic blood flow may exist within the joint space of children without abnormal structural changes of the synovium. Thus, if these new definitions of Doppler signal detection in synovitis for children are applied to the images for our study, the presence of synovitis would have been much less frequent in …
Address correspondence to Dr. Y. Zhao, MA 7.110, 4800 Sand Point Way NE, Seattle, Washington 98105, USA. E-mail: yongdong.zhao{at}seattlechildrens.org