MRU post-processing.

Dynamic magnetic resonance urography (MRU) scans acquired in conjunction with an injection of a contrast agent can be used to estimate a number of parameters that reflect renal function. This article discusses the methodologies and assumptions used in the estimation of these parameters, with special attention to the problem of deriving the concentration of the contrast agent from the change in the MR signal. The estimates of split renal function derived from MRU are in good agreement with those obtained using nuclear medicine studies. The time-intensity curves show subtle differences from those measured using nuclear medicine but still allow the transit of the contrast agent through the kidney to be assessed. Quantitative estimates of renal function (GFR) can be derived from MRU but have yet to be validated in a pediatric population.