US may be a reliable technique in the multiobserver scoring of GS parenchymal inhomogeneity of major SG in patients with established pSS. CD scoring of SG needs further standardization to be used in multicenter studies.

The MSUS assessment of only four tendons can be an additional feasible method to assess structural damage in RA patients.

Aims: Doppler ultrasonography assessment is mandatory nowadays for the complete description of rheumatic disease activity. Initially it was performed in semi quantitative way but recently the (fully) quantitative assessment is gaining more interest. In quantitative assessment, the ratio between total colorized and total pixels (CTR) is computed for the whole image or just for the region of interest (ROI). The frame with the highest amount of Doppler signal (also called worst case scenario image – WCSI) is usually the only one analyzed. The technique requires a very precise identification of WCSI from a certain number of consecutive frames, captured from the same position of the US probe, (and in most cases this is done manually). Our study examined the ability of both experienced and in-training sonographers to identify WCSI using a computerized analytical system as the gold standard.Materials and methods: The study analyzed 480 frame selections done in two distinct exercises. The WCSI and other 3 images with a 5%, 10% and respectively 20% lower level of CTR compared with WCSI were packed in one selection. All frames emerging from the same video clip were randomly presented to six experienced and six in training sonographers; the request was to select the frame with the highest CTR (WCSI) from each package (twenty packages in total). A similar exercise was performed with CTRs decreasing in steps of 2%.Results: In the first exercise the WCSI was correctly identified in 79.1% cases and in 67% of cases in the 2nd exercise. The interobserver agreement between experienced and in-trainer evaluators for the 1st exercise was 0.78 and 0.4 in the 2nd exercise.Conclusion: Using computerized analysis as the gold standard, we demonstrated a large heterogeneity across sonographers regarding their ability to identify the best Doppler image even from a small group of frames.

BackgroundMSUS helps the management of rheumatic diseases being able to show the level of tissue inflammation as Doppler signal. This signal might be scored in semi-quantitative and quantitative way. Several semi-quantitative scoring systems (SQS) have been developed but no one is subjective free. Quantitative Doppler score (QS) seems to be more objective (Terslev et al) being based on the computerized evaluation of the ratio between colored and non-colored pixels (CR). The present QS is based on the assessment of a single still image – usual the one with the highest Doppler signal; this approach does not exclude the subjective vulnerabilities (e.g. frame selection). We hypothesized that a Continuous quantitative assessment - CQS - (i.e. a quantitative assessment of all frames included in a video-loop) might be superior to single frame QS.ObjectivesTo test the ability of MS sonographers to identify the highest Doppler signal (highest CR) images from a group of frames extracted from the same loop. To test the reliability of a CQS method in rheumatoid arthritisMethods14 sonographers with high (4), medium (4) and basic (6) expertise in MSUS have participated in 3 phases of this project. In the 1st exercise we asked each participant to identify the frame with highest CR from a group of 4 frames (extracted from the same loop); the 4 frames had a CR decreasing in steps of 10%. The exercise included ten such groups. The 2nd exercise used a CR decreasing in steps of 2%. In the 3rd exercise the sonographers scored independently 10 MSUS video-clips and 10 static images of RA patients; the 0-3 SQS have been used. A blinded researcher analyzed each video and still image in CQS system twice; the average and the peak of CR have been noted for videos. CQS and SQS scores have been compared.ResultsIn 1st exercise the highest CR frame was identified in 7.5 (1.2) cases; in the 2nd exercise the performance was lower: 2.4 (2,1) cases out of 10. In both cases the agreement was poor. In the 3rd exercise the test-retest coefficients for CQS: 0.985 and 0.949 for average and, respectively, peak CRs. The average SQS scores correlated well with CQS CR (r=0.74 for average and r=0.76 for peak CR). The correlation was better for video clips (r=0.815) than for static images (r=0.546) - for average CR.ConclusionsContinuous quantitative assessment might be superior to single frame quantitative assessment in regular sonographers as the testers shown a moderate to poor performance in identification of the most significant picture. The test-retest performance and the higher correlation of CQS of video clips with SQS scores might recommend it as a reliable technique to assess Doppler loading in MSUS images.AcknowledgementsSf. Maria residents.Disclosure of InterestNone declared