MyPACS.net: Radiology Teaching Files > Case 31226666

previously visited DUPLEX RENAL COLLECTING SYSTEM WITH ECTOPIC URETERAL INSERTION
Contributed by: Brenda Grabb, Radiologist, Radiology and Imaging Consultants, Colorado Springs, Colorado, USA.
Patient: 3 year old female
History: 3 year old female: known duplex left renal collecting system by ultrasound. She presents with persistent incontinence. By ultrasound, it was difficult to determine the site of insertion of the left upper pole moiety ureter.
Images:[small]larger

Fig. 1: US of the right kidney demonstrates no collecting system dilatation.

Fig. 2: US of the left kidney demonstrates moderate dilatation of the upper pole moiety system and mild prominence of the lower pole pelvis.

Fig. 3: US of the bladder demonstrates the dilated left upper pole ureter reaching the level of the bladder.

Fig. 4: Sagittal T2 weighted MR image demonstrates marked dilatation and toruosity of the left upper pole ureter.

Fig. 5: Coronal T2 weighted MR image demonstrates dilatation of the upper pole system creating partial mild obstruction of the left lower pole at the UPJ.

Fig. 6: Coronal T2 weighted MR image demonstrates marked dilatation and tortuosity of the left upper pole ureter.

Fig. 7: Axial high resolution T2 weighted image of the kidney demonstrates healthy appearing parenchyma of the left upper pole.

Fig. 8: Reformatted 3D image clearly shows the ectopic insertion of the left upper pole ureter separate from the urinary bladder.

Fig. 9: Reformatted 3D image clearly shows the ectopic insertion of the left upper pole ureter separate from the urinary bladder.

Fig. 10: Post gadolinium image demonstrates no obstruction on the right where there is a bifid pelvis. There is a marked delay in excretion by the left upper pole as well as a mild delay in excretion in excretion by the left lower pole which was seen to be mildly and incompletely obstructed both at the UPJ (on an earlier image) and within the lower ureter (on this image).

Fig. 11: Axial T2 weighted MR image demonstrates the dilated left upper pole ureter crossing over the collapsed vagina.

Fig. 12: Axial T2 weighted MR iamge demonstrates the lft upper pole ureter inserting into the distal urethra.
Findings:

Ultrasound examination demonstrates no collecting system dilatation on the right but moderate dilatation of the left upper pole moiety collecting system all the way to the urinary bladder. There is mild prominence of the left lower pole moiety pelvis.

MR urography demonstrates no collecting system dilatation on the right but a bifid pelvis present. On the left, the upper pole moiety demonstrates sereve dilatation of the pelvis and calyces and severe dilatation and toruosity of the ureter. This dilated ureter creates mild, incomplete obstruction of the left lower pole moiety pelvis at the UPJ as well as of the distal ureter due to its mass effect.

The insertion of this left upper pole moiety ureter is ectopic, into the distal urethra.

Despite the ectopic location of the ureter, the left upper pole parenchyma appears nondysplastic and quite healthy.

Diagnosis: Duplex left renal collecting system with ectopic insertion of the upper pole moiety ureter into the distal urethra.
Discussion:

Persistent incontinence in female children raises the question of a duplex system with an ectopic ureter. Often the more ectopic the insertion, the more dysplastic the upper pole moiety.

The Weigert-Meyer rule states that, in a duplex system, the upper pole ureter is prone to obstruction and hydronephrosis while the lower pole ureter is prone to vesicoureteral reflux and pyelonephritis. The uper pole ureter inserts more medially and more inferiorly if it inserts into the bladder, but it may insert into the vagina or into the urethra. Males are not prone to incontinence as they have an external urethral sphincter. The upper pole ureter may be associated with a ureterocele.

References:

chorus.rad.mcw.edu Weigert Meyer

C.E.Kahn, Jr. 2002

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Additional Details:

Case Number: 31226666Last Updated: 09-20-2009
Anatomy: Genitourinary (GU)   Pathology: Congenital
Modality: MR, USAccess Level: Readable by all users
Keywords: weigert meyer; pediatric;

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