MR urography in children: how we do it

Abstract

In this article we introduce the topic of MR urography in children, focusing on the details required to obtain consistently high-quality scans. Much of the information presented is based on our experience during the last 7 years. We have performed almost 1,000 MR urograms in children, and the technique has evolved considerably during this time. We have learned through trial and error and have improved our protocols to the point that our approach is now standardized and reliably generates high-quality studies. From this standardized protocol, further refinements in technique can be readily implemented. It is important to remember that this clinical application is in its infancy and will improve significantly with further technical development. This paper provides an overview of the practical issues associated with obtaining high-quality scans as well as an introduction into the interpretation of MR urograms.

Magnetic resonance nephrography for planning of laparoscopic partial nephrectomy in a pediatric case of ureteral triplication

“…Dynamic MR nephrography has been recently described as additional diagnostic tool for selected pediatric urological cases [2,3]. This method combines functional and morphologic analyses of the urinary tract in one single investigation.…”

“…This method combines functional and morphologic analyses of the urinary tract in one single investigation. Magnetic resonance nephrography provides a higher spatial resolution compared with sonography, allows a more precise definition of regions-of-interest than does MAG3 renal scan, and does not use ionizing radiation [2,[4][5][6]. Renal scarring could be ruled out, and the split function could be assessed sufficiently through MR urography.…”

“…This technique permits the quantitative recording of the course of contrast-medium concentration within the collecting systems. Moreover, the time-dependent change of contrast-medium concentration in the collecting system can accurately be assessed without signal contamination from the renal parenchyma [2,4,5]. Because costs for MR nephrography are comparable with those of renal scintigraphy, the possibly required sedation for small children and the administration of contrast material might be the only disadvantage.…”

Pediatric MR urography: Indications, techniques and role in uroradiology

“…The intravenous hydration before the scanning is crucial for reducing the concentration of the contrast agent in the renal pelvis and for optimal distention of the urinary tract. The administration of furosemide 15 minutes prior to the contrast agent injection has the same purpose in addition to servin as the stress test for the the ureteropelvic junction (4,5). Optimally the patient is scanned in the prone position (6).…”

“…Optimally the patient is scanned in the prone position (6). The functional analysis is based primarily on the post-contrast dynamic sequences (the regular dose of contrast agent is 0.1 mmol/kg gadolinium-DTPA) (4). For the post-contrast scan we employ 3-D T1-weighted gradient echo sequence with fat saturation ("volumetric interpolated breath-hold examination" -VIBE -Siemens®, Erlangen, Germany) with the adjustment of parameters for a single series not to exceed 11 seconds and with each series have the same number of slices.…”