AB0798 IS THERE A REPRODUCIBILITY OF THE HISTOGRAM AND GRAY SCALE IN ECOEXTRUCTURAL DAMAGES IN RHEUMATOTOLOGICAL DISEASES?
Authors: J. A. Mendonça, I. Siste de Almeida Aoki, C. C. Cavuto, V. A. Leandro-Merhi, J. L. B. D. Aquino
Journal: Annals of the Rheumatic Diseases (2021)

Background: The gray scale (GS) in high resolution ultrasound is already well validated for use in rheumatological diseases, but the color map or the histogram, can be considered a new proposal, to better define and complement the echotextural damages detection 1 . Objectives: To calculate the lesions area measures reproducibility index in arthropathies, between 3 blind evaluators and correlate these measures using the GS and the histogram. Methods: Observational and retrospective study approved by the ethics committee of the Pontifical Catholic University of Campinas, with the opinion number: 1.526.307. A total of 29 patients have been assessed (31% males and 69% females) on period 2014 to 2019 in Rheumatology service. A MyLab 50 -Esaote equipment was used with frequency transducer that ranged between 6.0 and 18.0 MHz, 10 different area measures were performed from each recorded images previously, by the GS and the histogram. Statistical analysis: Spearman’s correlation coefficients, Lin’s concordance coefficient (CCC) and the intraclass correlation coefficient (ICC) and their respective 95% confidence intervals, with the SPSS software package for Windows v. 17.0 (SPSS Inc., Chicago, IL, USA). Results: Average age 43.5 ± 21.5 years of age; with disease duration that varied between ≤ 1 month (48.3%) and ≥36 months (24.1%); with the following diseases: juvenile idiopathic arthritis (17.24%); osteoarthritis (13.79%); psoriatic arthritis (13.79%); undifferentiated spondyloarthritis (3.44%); gout (20.68%); rheumatoid arthritis (27.58%) and reactive arthritis (3.44%). A total of 840 measures of exudative (27.58%), proliferative (27.58%) and snowstorm appearance (6.89%) synovitis were performed; femoral-condyle cartilage (3.44%); synovial cyst (3.44%); paratendinitis (6.89%); calcification (3.44%); nail enthesitis (3.44%); tenosynovitis (6.89%) and tophi (10.34%) (Figure 1). The concordance correlation coefficient showed values closer to 1; p &lt;0.001, the intraclass correlation coefficients with excellent reproducibility (ICC ≥ 0.75); p &lt;0.001, always in relation to the three evaluators (Table 1) and the Spearman correlation between the GS and the histogram ranged from rs = 0.665 to rs = 1,000; p &lt;0.001. Conclusion: The histogram can be considered an image method to better identify echotextural damages. References: [1]Mendonça J, Provenza J, Guissa V, et al AB1059 2D Histogram Ultrasound and 3D Ultrasound Correlation in Rheumatic Diseases Annals of the Rheumatic Diseases 2015; 74:1253-1254. Table 1. Concordance Correlation Coefficient (CCC) and Intraclass Correlation Coefficient (ICC): Evaluators GS - CCC (IC 95% ) p-valor Histogram (IC 95% ) p-valor 1 e 2 0,998 (0,994-0,999) &lt;0,001 0,999 (0,995-1,000) &lt;0,001 1 e 3 0,998 (0,995-0,999) &lt;0,001 0,999 (0,995-1,000) &lt;0,001 2 e 3 0,992 (0,980-0,997) &lt;0,01 0,996 (0,979-0,999) &lt;0,01 Standard by US 2D ICC p-valor GS 0,997 (0,992-0,999) &lt;0,001 Histogram 0,998 (0,992-0,999) &lt;0,001 Legends: Gray Scale (GS). Figure 1. Patient with gout: A and B: Tophi area measures (star) in right metatarsos and efusion (arrow) by GS (45 mm 2 ) and histogram (39 mm2), respectively. Disclosure of Interests: José Alexandre Mendonça Speakers bureau: Novartis, Janssen, Bristol, UCB, Isabella Siste de Almeida Aoki: None declared, Caique Chagas Cavuto: None declared, Vânia Aparecida Leandro-Merhi: None declared, José Luis Braga de Aquino: None declared