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[Magnetic resonance urogram as alternative to i.v. urography. Report of 3 cases. Review of the literature].

OBJECTIVES
Intravenous urography (IVU) has been classically considered as an essential examination in the great majority of urologic diseases due to the great amount of information that supplies both functional and morphological, mainly for ureteral abnormalities where other exams do not reach enough definition. Nevertheless, there are cases in which it is not possible to perform an intravenous urography due to allergy to iodine contrasts or renal failure with impossibility of contrast excretion.


METHODS
We report three cases which represent the example of the indications of MRI urography as an alternative to IVU in cases in which this latter cannot or should not be performed.


RESULTS
MRI urography is completely accepted as a diagnostic technique for urologic diseases as an alternative to IVU. It has advantages, such as obtaining images in multiple planes, avoiding the use of ionizing radiation, that there is no evidence of it causing cell damage, that it does not require glomerular elimination of any substance so it can be used in patients with renal failure and allergy to iodine contrasts.


CONCLUSIONS
The use of MRI urography results in an advantage for patients with renal failure, iodine contrasts allergy, or greater risk of contrast nephrotoxicity as it is the case of renal transplant patients.