Magnetic resonance urography in the assesment of congenital urinary system dilatation in pediatric patients

Abstract

The aim of this study is to assess combined static-dynamic magnetic resonance (MR) urography in the evaluation of urinary tract anomalies in infants and children. Thirthynine patients with urinary tract anomalies underwent retrospective examination between 2009- 2012, with combined static dynamic MR urography. A combination examination involved use of a static T2-weighted thick slap spin-echo sequence and a dynamic T1-weighted tree-dimensional spoiled gradient echo- recalled sequence with gadopentetate dimeglumine-DTPA and furosemide application. Morphologic results were compared with those of ultrasonography and, when available, surgery. The dynamic sequence was used to calculate renal transit time (RTT), split renal function from renograms generated from parenchymal regions of interest and to assess urinary excretion from whole-kidney renograms. Results were compared with those of diuretic renal scintigraphy for split function and urinary excretion. Urinary system dilatations caused by stenosis at the ureteropelvic (n=16), ureterovesical (n=4) junctions and within the ureter (n=6), posterior urethral valve (n=1), postoperative urethral obstruction (n=1), neurogenic bladder (n=1) and nonstenotic dilatation (n=4) and urinary tract anomalies, double collecting system (n=4) and isolated urinary tract anomalies (n=2) were clearly depicted. For morphologic evaluation, sensivity of MR urography compared with surgery calculated 82.75% and for split renal function, sensivity of dynamic MR urography compared with diuretic renal scintigraphy (DRS) calculated 80%. For urinary excretion, MR urography and DRS showed strong agreement. MR urografi is a modality with which urinary system pathologies could be both morphologically and functionally evaluated with high accuracy and does not use ionizing radiation. But it has disadvantages for example, children need sedation during examination, results cannot be compared with enough clinical trials because of ethical reasons and some technical incapabilities. But we think with some technical improvements, MR urography can be applied in diagnosis and follow up of urinary system abnormalities in children with high degree of confidency.

Keywords

• Magnetic resonance functional imaging
• Magnetic resonance urography
• Pediatric patient
• Urinary anomalies

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