The ultrasound image labeled “SAG LT KIDNEY MID” demonstrates a left kidney with two separate, centrally located echogenic renal sinuses separated by intervening renal parenchyma. This appearance is classic for a duplicated collecting system.
A duplicated collecting system (also known as duplex kidney) is a congenital anomaly in which a single kidney contains two separate pelvicalyceal systems. It may be complete (with two ureters) or incomplete (partial duplication of ureters). This condition is one of the most common congenital anomalies of the urinary tract.
Sonographic Features of a Duplicated Collecting System:
Two separate central echogenic renal sinus regions seen within one kidney
Intervening parenchyma between the two sinuses
May show associated findings: hydroureteronephrosis (especially of upper pole moiety), ureterocele
Best visualized in sagittal plane
Differentiation from other options:
A. Horseshoe kidney: Shows fusion of the lower poles of the kidneys, typically located anterior to the aorta in the midline—not demonstrated here.
B. Crossed renal ectopia: One kidney is located on the opposite side of the body; this image shows a normally positioned kidney.
C. Prominent renal column (column of Bertin): May mimic a mass, but does not produce two separate sinuses as shown here.
[References:, Rumack CM, Wilson SR, Charboneau JW, Levine D. Diagnostic Ultrasound. 5th Edition. Elsevier, 2018. Chapter: Kidneys, pp. 210–215., American Institute of Ultrasound in Medicine (AIUM). Practice Parameter for the Performance of a Renal Ultrasound Examination, 2020., Radiopaedia.org. Duplex collecting system: https://radiopaedia.org/articles/duplex-collecting-system, , ]
Submit