OC.12.1 ACCURACY OF ULTRASONOGRAPHY IN ASSESSING DISEASE ACTIVITY IN PEDIATRIC ULCERATIVE COLITIS: PRELIMINARY RESULTS OF A TWO-CENTER STUDY. (May 2022) - Terracciano, F.; Marra, A.; Bossa, F.; Dirodi, A.; Ippolito, M.A.; Carparelli, S.; Pastore, M.R.; Valvano, M.R.; Marseglia, A.; D'Altilia, M.; Ferrara, D.; Bucci, C.; et al.