Conversion and reliability of two urological grading systems in infants: the Society for Fetal Urology and the urinary tract dilatation classifications system.

Correspondence between the systems was poor using a recommended re-categorization (SFU-A). An alternative re-categorization (SFU-B) was found to be more appropriate for establishing correspondence between the systems. Both systems were reliable, with good intra- and inter-observer agreement for the assessment of infant kidneys, but the UTD system had better inter-observer agreement.