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Updated: Mar 19, 2026

Author Spotlight: Developing a Bedside Protocol for Kidney and Genitourinary Ultrasonography
Published on: June 21, 2024
MR Urography Revealing Renal Physiology: Compensatory Changes in Duplex Kidneys
Kumar K Shashi1, Harsha Garg1, Sila Kurugol1
1Boston Children's Hospital, Department of Radiology, Boston, MA.
Objective:
To use DCE-MRU to evaluate the physiological differences between duplex kidneys with and without obstructed moieties.
Methods:
Consecutive patients who underwent DCE-MRU studies between January 2019 and March 2021 for evaluation of duplex kidneys were included. The study population consisted exclusively of patients with duplex kidneys (complete ureteral duplication), divided into group A (duplex kidneys with one obstructed moiety, n = 5) and group B (duplex kidneys without obstruction, n = 5). Utilizing prior described techniques, filtration rate (Ft) parameter, which is a measure of renal filtration, was calculated of each renal moiety and compared between the two groups.
Results:
Five patients in group A were compared to 5 patients in group B. In group A, the non-obstructed moiety showed relative increased Ft or hyper filtration compared to the normal contralateral side. Those in group B did not show increased Ft.
Conclusion:
MRU, with its high spatial and temporal resolution and its ability to calculate Ft, provides a non-invasive assessment of renal physiology, and this is the first report of renal compensation occurring within a kidney where one moiety of the kidney demonstrates hyperfiltration, perhaps as a compensation for the stressed obstructive state of the other pole.
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The PCT is the initial segment of the renal tubule, extending from the Bowman's capsule that encloses the glomerulus. Its convoluted structure and microvilli-lined cells increase the surface area for reabsorption. The PCT reabsorbs glucose, amino acids, sodium, and water from the filtrate, ensuring essential...

