Three-dimensional volumetric ultrasonography. Does it improve reliabililty of musculoskeletal ultrasound?

Abstract

OBJECTIVE: To compare the interobserver reliability of three-dimensional (3D) volumetric ultrasonography (US) and 2D real-time US in detecting inflammatory and destructive changes in rheumatoid arthritis (RA) wrist and hand. METHODS: Two RA patients were selected by a rheumatologist who performed independently a grey-scale and power Doppler (PD) volumetric acquisition at three anatomic sites in their more symptomatic wrist/hand using two identical scanners equipped with 3D volumetric probe. Twelve rheumatologists expert in MSUS were randomly assigned to a US scanner and a patient. In the first part of the study, each group of experts blindly, independently, and consecutively performed a 2D real-time grey-scale and PD US investigation of inflammatory changes and/or bone erosions at the three anatomic sites. In the second part of the study, each group of investigators blindly evaluated the same pathologic changes in the 6 volumes from the patient not scanned by them. RESULTS: The kappa values were higher for 3D volumetric US than for 2D US in the detection of synovitis/tenosyno-vitis (0.41 vs. 0.37) and PD signal (0.82 vs 0.45) and in the PD signal grading (0.81 vs. 0.55). CONCLUSION: 3D volumetric US may improve the interobserver reliability in RA multicentre studies.