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Hydronephrotic lower moiety of duplex systems: Observations using diuresis renography
Jane S Kim1, Eglal Shalaby-Rana1, Aaron Krill2
1Division of Diagnostic Imaging and Radiology, Children's National Hospital, 111 Michigan Avenue NW, Washington, D.C. 20010, United States of America.
Clinical Imaging
|April 5, 2024
Summary
Hydronephrosis of the lower moiety in duplex kidneys is rare but can cause obstruction. MAG-3 diuresis renography helps evaluate and manage this condition, which often presents dynamically.
Area of Science:
- Pediatric Urology
- Diagnostic Imaging
- Renal Physiology
Background:
- Duplex kidney systems are common congenital anomalies.
- Lower moiety hydronephrosis in duplex systems can mimic ureteropelvic junction obstruction.
- Non-refluxing lower moiety hydronephrosis requires specific diagnostic approaches.
Purpose of the Study:
- To characterize the prevalence and behavior of hydronephrosis in the non-refluxing lower moiety of duplex kidneys.
- To evaluate the utility of MAG-3 diuresis renography in diagnosing and managing this condition.
- To compare findings with ureteropelvic junction obstruction in single renal systems.
Main Methods:
- Retrospective analysis of over 5000 MAG-3 diuresis renograms in 2025 patients.
- Identification of cases with lower moiety duplex kidney hydronephrosis, excluding reflux or hydroureter.
- Review of kidney function, drainage parameters, and patient outcomes.
Main Results:
- 19 renal units in 18 patients were identified with lower moiety hydronephrosis.
- Antenatal hydronephrosis cases showed variable drainage patterns, with some worsening over time.
- 5 of 6 patients presenting with Dietl's crisis had obstructive drainage, necessitating surgery.
Conclusions:
- Hydronephrosis of the lower moiety in duplex systems is uncommon and exhibits dynamic behavior.
- This condition can present with acute obstruction, similar to single-system ureteropelvic junction obstruction.
- MAG-3 diuresis renography is crucial for evaluating and guiding the management of these cases.
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