Detection of a poorly functioning malpositioned kidney with single ectopic ureter in girls with urinary dribbling: imaging evaluation in five patients.
OBJECTIVE
Some girls with lifelong continuous dribbling of urine despite successful toilet training have urographic or sonographic evidence of only one kidney. Such girls are likely to have a contralateral, poorly functioning, nonvisualized, malpositioned kidney with a nonduplicated collecting system and ureter draining through an ectopic orifice. Our objective was to analyze our experience with this group of patients to determine how best to confirm the presence and show the location of this abnormal kidney.


METHODS
We reviewed the medical records and imaging studies of five such girls who were first seen at our hospital between 1975 and 1993 to determine how their poorly functioning, malpositioned kidney was detected. The imaging studies included sonography, excretory urography, vaginography, retrograde and intraoperative antegrade ureterography, renal cortical scintigraphy using 99mTc-dimercaptosuccinic acid, CT, and MR imaging.


RESULTS
All the abnormal kidneys were located on the left side. Excretory urography and sonography showed the abnormal kidney in only one of these five patients. In a second girl, retrograde ureterography showed the ureter of the dysplastic kidney after an ectopic ureteral orifice was discovered in the vagina during examination under general anesthesia. In a third, reflux from the vagina during a vaginogram showed the abnormal kidney. Renal cortical scintigraphy using dimercaptosuccinic acid showed the dysplastic, malpositioned, poorly functioning kidney in three girls. CT with special attention to the region of radionuclide uptake seen on scintigram showed the location of the dysplastic kidney more precisely in two patients.


CONCLUSIONS
A girl with continuous dribbling of urine despite normal voiding habits whose excretory urogram and sonogram reveal only one kidney should have a dimercaptosuccinic-acid scintigram as the next imaging evaluation. A CT scan through the area of interest as determined by the dimercaptosuccinic-acid scintigram will more accurately localize the often ectopic kidney, thus facilitating its removal.
Gharagozloo
A M
AM
Department of Radiology, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
Lebowitz
R L
RL
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D000013:Congenital Abnormalities / Q000175:diagnosis; D005260:Female; D006801:Humans; D007668:Kidney / Q000002:abnormalities* / Q000000981:diagnostic imaging; D011859:Radiography; D011877:Radionuclide Imaging; D014463:Ultrasonography; D014513:Ureter / Q000002:abnormalities* / Q000000981:diagnostic imaging; D014555:Urination Disorders / Q000209:etiology*