1 Pediatric Rheumatology, Seattle Children's Hospital, Department of Pediatrics, University of Washington, and Center for Clinical and Translational Research, Seattle Children's Hospital; yongdong.zhao@seattlechildrens.org.
2 Pediatric Rheumatology, Seattle Children's Hospital, Department of Pediatrics, University of Washington.
3 Pediatric Radiology, Seattle Children's Hospital, University of Washington.
4 Pediatric Rheumatology, Seattle Children's Hospital, Department of Pediatrics, University of Washington, Seattle, Washington, USA.