Toward Standardized Musculoskeletal Ultrasound in Pediatric Rheumatology: Normal Age‐Related Ultrasound Findings

Abstract

Objective. The Outcome Measures in Rheumatology Ultrasound Task Force has recently started to work on the validation and standardization of musculoskeletal ultrasound (MSUS) examination in children in order to improve its applicability to joint examination. Methods. This was a prospective multicenter study performed by 4 experts in pediatric MSUS, who independently collected representative images using predefined scanning procedures of 4 joints (knee, ankle, wrist, and second metacarpophalangeal joint) in different predefined age groups. Researchers were allowed to use their own settings (B-mode and Doppler) in order to get the best quality image and highest sensitivity for low blood flow. Images were evaluated for quality parameters and an atlas was created with the best images. An equipment comparative study was performed by a single examiner using 2 different types of machines. Results. Sixty-four healthy children were scanned. The quality of evaluated images, obtained by predefined scanning positions, was highly comparable among the examiners. The B-mode images clearly showed age-related variations of joint findings, while Doppler images showed the presence of blood flow, particularly within the epiphyseal cartilage of the children at a younger age. There was a high to good level of consistency between images obtained from the 2 different ultrasound machines. Conclusion. The study shows a systematic method for ultrasound examination of children at different age groups. Additionally, a baseline collection of images was developed, showing blood vessels in the joints examined. The present study could provide a framework for ongoing MSUS studies as well as for clinical practice in pediatric rheumatology.

Preliminary Definitions for the Sonographic Features of Synovitis in Children

“…Definitions for the US appearance of synovitis in children were successfully developed through a consensus process and validated on still images. This development represents another important step for a more reliable use of US in children, following the definition of findings of the normal joint and the publication of standard views to assess various joints . At the same time, these definitions clearly should be validated further in a patient‐based practical exercise.…”

“…Following the agreement on definitions, all the participants were then invited to submit B‐mode and Doppler images of synovitis of the following joints: metacarpophalangeal (MCP), the wrist, and tibiotalar joints. Separate images were submitted for the following 4 age groups: toddler and preschool (ages 2–4 years), young children (ages 5–8 years), preadolescent (ages 9–12 years), and teenagers (ages 13–16 years) . Participants were asked to acquire the scans using standardized views, including longitudinal midline scans and a dorsal approach for MCP and wrist, as agreed in a previous exercise .…”

“…Separate images were submitted for the following 4 age groups: toddler and preschool (ages 2–4 years), young children (ages 5–8 years), preadolescent (ages 9–12 years), and teenagers (ages 13–16 years) . Participants were asked to acquire the scans using standardized views, including longitudinal midline scans and a dorsal approach for MCP and wrist, as agreed in a previous exercise . The images also had to fulfill minimum quality criteria, including a thin layer of gel at the top of the image, clear visibility of bone contours and correct size of the Doppler box, i.e., the Doppler box had to include the relevant joint structures and extend to the top of the image.…”

“…Other aspects described for a normal pediatric joint include the growth plate, hyperechoic echoes representing vascular channels, and the precise differentiation of the joint capsule from the synovial recess . Finally, recommendations for the standardized assessment of various joints have also been published .…”

Correction: Prevalence, incidence and progression of hand osteoarthritis in the general population: the Framingham Osteoarthritis Study

“…[11][12][13][14] Studies on US of joints in healthy children and in JIA have already been published. [15][16][17][18][19][20][21] It has been suggested that US may be more sensitive in detecting joint inflammation in patients with JIA than the clinical evaluation. [22][23][24][25][26][27] However, the role of US-detected synovitis when clinical manifestations in JIA are absent is unknown.…”