Magnetic resonance imaging of the dysplastic renal moiety and ectopic ureter

PURPOSE: We determined the role of magnetic resonance imaging (MRI) in symptomatic children with clinically suspected and radiologically occult dysplastic renal moieties and ectopic ureters. MATERIALS AND METHODS: We reviewed clinical, imaging, cystoscopic, surgical and histological findings in 6 symptomatic children 1 to 15 years old with dysplastic renal moieties. RESULTS: After multiple conventional imaging studies failed to delineate urinary tract anatomy MRI provided detailed multiplanar images of dysplastic renal moieties that were diagnostic and predictive of subsequent intraoperative findings. Dysplastic upper pole moieties identified in 4 children were associated with ectopic ureters inserting into the vagina, prostatic urethra, bladder neck and bladder neck ureterocele in each. A solitary kidney with contralateral blind-ending ectopic ureters inserted into the bladder base in 2 cases. Pelvic cystic structures visualized by ultrasound in 3 patients were tortuous distal ureters on MRI. MRI specifically identified ureteral insertion sites that were not evident in 3 of the 5 patients who underwent cystoscopy. CONCLUSIONS: MRI may facilitate diagnosis, guide cystoscopy and aid in preoperative planning in children with poorly functioning renal moieties and ectopic ureters.