Magnetic resonance urography in children – when and why?

BACKGROUND: The aim of the study was to determine the potential of magnetic resonance urography (MRU) in evaluation of paediatric urinary tract pathologies. PATIENTS AND METHODS. Twenty-one paediatric urological patients were evaluated with T1, T2 prior and after and 3D gradient echo sequences after the contrast administration. Results were compared with findings obtained with ultrasound which was performed to all of patients, intravenous urography performed to 14 patients with the diagnosis of hydronephrosis and voiding cystouretrography performed to 6 patients where hydronephrosis was suspected to be caused by vesicoureteral reflux (VUR). RESULTS: MRU not only established the cause of hydronephrosis in all 14 cases (5 ureteropelvic junction (UPJ) stenosis, 1 functional stenosis, 3 residual hydronephrosis, 1 combination of UPJ and vesico-ureteric junction (VUJ) stenosis with hydromegaureter, 2 fetal ureters and 3 insufficient broad ureteral orifices), but gave additional information about existing pathological conditions in all of patients compared to other previously performed examination (1 caliceal lithiasis, 4 UPJ stenosis, 1 VUJ stenosis, 1 neurogenic bladder, 1 hypotonic ureter, 1 urinary infection, 1 duplication of pelvis and ureter, 1 urinary retention and 1 fetal ureter). Other MRU findings were: 3 polycystic kidney disease, 1 caliceal cyst, 2 simple renal cysts, 1 long hypotonic twisted ureters and 1 hypertrophied column of Bertini. CONCLUSIONS: Because of the ability to acquire high contrast and spatial resolution images of the whole urinary tract in any orthogonal plane, MRU enables a precise detection and differentiation of pathological urological conditions. We believe that in the future, because of its advantages, MRU will replace traditional methods in the evaluation of urinary tract pathologies.