Lence T, Lockwood GM, Storm DW, et al. - Researchers sought to determine whether pyramidal thickness (PT) measurements have utility in cases with SFU (Society of Fetal Urology) grades 3 and 4 hydronephrosis. For this purpose, they examined the inter-rater reliability of PT measurements as well as the correlation between relative kidney function on nuclear renal scan and PT, and also assessed the pyeloplasty predictive capability of PT alone and together with SFU grade and/or other sonographic measurements in multivariate statistical models. A total of 110 children with SFU grade III and IV hydronephrosis were analyzed retrospectively. Findings demonstrated the reliability as well as usefulness of PT measurements for characterizing the hydronephrotic kidney parenchyma, and a significantly more frequent occurrence of a PT > 3mm was evident in patients with a differential renal function >= 45%. PT alone was identified as a predictor of subsequent pyeloplasty (AUC=0.781). More accuracy was conferred by a novel pyeloplasty predictive score (PPS) using only objective measurements including PT, anteroposterior pelvic diameter, and renal length vs a PPS that included SFU grade (AUC of 0.885 and 0.866, respectively). Considering utilization of PT < 3mm as a criterion for ‘thinned parenchyma’ in the SFU, urinary tract dilation, and other hydronephrosis grading systems is recommended if confirmed by additional studies.