Purpose or Case Report: To determine the cause of obstructive hydronephrosis using fMRU in pediatric patients with inconclusive conventional studies.
Methods & Materials: A prospective, non-experimental, exploratory study in pediatric patients with moderate to severe hydronephrosis for whom conventional studies were inconclusive to determine obstruction as a cause was performed.
Patients included did not have renal impairment nor vesicoureteral reflux.
fMRU was performed with a 1.5 T device and our protocol included both morphological and functional studies before and after gadolinium injection.
For functional analysis we used Khrichenko and Darge Software, available at http://www.CHOP-fMRU.com.
Image analysis was performed by two radiologists and the final diagnosis was made by consensus.
The results of fMRU were correlated with surgical findings in the cases that underwent surgery and patients were followed for a period of 1 year after surgery.
Results: 10 patients were included in the study with a total of 20 renal units analyzed. 12 units had hydronephrosis, 8 moderate and 4 severe. 8 renal units were normal.
The fMRU was able to determine that 11 cases were obstructive hydronephrosis and one was inconclusive. Also, it was possible to determine if the obstructive systems were unbalanced or not. Regarding the level of obstruction, ureteropelvic junction stenosis was the most frequent finding. Those findings were certificated during surgery.
Differential renal function was estimated in 9 patients with good correlation when compared to nuclear medicine scans.
All the cases that underwent surgery improved the hydronephrosis and they are in good conditions 1 year later.
Conclusions: fMRI is a good method to asses obstruction as a cause of hydronephrosis in cases where conventional studies are inconclusive.
fMRU provides all the information needed to make clinical decisions without the use of ionizing radiation. Its disadvantage is the requirement for anesthesia and / or sedation in young children.