Dynamic MRI and isotope renogram in the functional evaluation of pelviureteric junction obstruction: A comparative study

Özet

Objective: The aim of this study was to evaluate and compare the diagnostic accuracy of dynamic contrast- enhancedmagnetic resonance imaging (dMRI) and isotope renogram in the functional evaluation of pelviuretericjunction obstruction (PUJO).Material and methods: Forty-two patients included in the study were investigated with isotope renogramand subsequently, subjected to dMRI. Time-activity curves were generated for both isotope renogram anddMRI. Out of the 42 cases, 9 cases were conservatively managed. Thirty-three cases were taken up for surgicalintervention.Results: Of 33 patients taken up for surgical intervention, 12 underwent laparoscopic nephrectomy and 21 ofthem pyeloplasty. The mean glomerular filtration rates (GFRs) as measured by isotope renogram and dMRIwere 22.5+4.2 mL/min and 23.8+3.1 mL/min respectively. The calculation of GFR by isotope renogram,showed good correlation with that of dMRI with correlation coefficient of 0.93. The dMRI was able to revealthe functional status of the renal unit accurately. dMRI did not yield false positive results with 20 of 21 patientsscheduled for pyeloplasty and 11 of 12 patients scheduled for nephrectomy. Isotope renogram had a false positiveresult in 3 cases compared with surgical diagnosis.Conclusion: Analysis of renal function using dMRI yielded results comparable to those of renal scintigraphy,with superior spatial and contrast resolution. It was also better in prompting management decisions with respectto the obstructed systems. dMRI can be used as a “one stop imaging examination” that can replace differentimaging methods used for morphological, etiological and functional evaluation of PUJO.