Abstract Objective To examine the reliability of contrast-enhanced MRI (CEMRI) and contrast-enhanced ultrasound (CEUS) for grading arthritis. Materials and methods Prospective study on 1–18-year-olds with juvenile idiopathic arthritis (JIA), performed during 2023/2024. All had CEUS and CEMRI of the knee on the same day. Two observers independently scored the US-video-clip for inflammation (0–3 scale), with a second reading after 6 weeks. Using VueBox®, peak enhancement (PE), time to peak (TTP) and wash-in area under the curve (WiAUC) were measured by both observers, separately. The MRIs were scored for inflammation (0–3 scale) twice by two observers. Peak enhancement intensity (PEI), TTP and initial area under the curve (iAUC) (Syngo.via®) were measured. Results Fifty-two patients (35 females), median age 12.4 years (IQR 8.9–15.6 years), were included. CEUS showed almost perfect intra/interreader agreement for the degree of overall inflammation (intrareader kappa 0.90 0.83–0.98, interreader kappa 0.85 0.76–0.93). Interreader PE and WiAUC agreement was excellent (ICC 0.99 95% CI 0.99–1.00 and 0.97 95% CI 0.95–0.98, respectively), while TTP performed moderately (ICC 0.66 95% CI 0.40–0.80). On CEMRI, intra/interreader agreement for overall synovial inflammation was almost perfect (intrareader kappa 0.94 95% CI 0.88–1.00; interreader kappa 0.92 95% CI 0.85–1.00). Interreader PEI and iAUC agreement was excellent (ICC 0.99 95% CI 0.98–0.99 and 0.98 95% CI 0.97–0.99, respectively), while TTP had good agreement (ICC 0.76 95% CI 0.59–0.86). Conclusion Subjective grading of synovial inflammation on a 0–3 scale demonstrated high reliability for both CEUS and CEMRI. Both methods have excellent relative reliability (ICC) for quantitative measurements; however, their absolute precision (LoA) is poor. Key Points Question Are CEUS and CEMRI reliable tools to grade the activity of knee-joint arthritis in children with juvenile idiopathic arthritis? Findings Subjective grading of arthritis performed well within and between observers for both CEUS and CEMRI. Both methods provide reliable dynamic measurements; however, their precision is poor. Clinical relevance CEUS offers high-precision, real-time imaging for grading active knee-joint inflammation in children with juvenile idiopathic arthritis, with future potential to replace the current standard of CEMRI. Graphical Abstract
Dias et al. (Fri,) studied this question.