Evaluation of Functional MR-Urography in Complex Obstructive Uropathy of Infants: Comparison to the Conventional Diagnostic Algorithm – A Pilot Study

Abstract

Objectives:

To analyze the impact of functional magnetic resonance urography (fMRU) on the therapeutic management in infants with complex obstructive uropathy (OU) compared to the conventional diagnostic algorithm [CDA, ultrasound, radioisotope nephrography (RN)].

Methods:

Retrospective analysis on 10 consecutive infants [female, n=3; male, n=7; age, 10.7 (2–17) months] with OU. Patients were examined according to CDA. If CDA revealed inconclusive results, fMRU was performed additionally. Split kidney function was assessed by RN [single kidney function (SKF)] and fMRU [volumetric differential renal function (vDRF)]. Findings were presented to an interdisciplinary truth-panel in a 2-step decision process (with and without fMRU). Clinical decision was determined.

Results:

CDA indicated surgical intervention in 8 patients and conservative treatment in 2. Information by fMRU changed treatment strategy in 3 patients and led to the modification of the initially chosen surgical approach in 8 cases. The comparison of SKF and vDRF was not possible in 1 patient, whereas concordance was observed in 7 patients. SKF and vDRF differed >5% in 2 patients.

Conclusions:

fMRU has potential to improve therapeutic management of OU in infants. If surgical treatment is advised, the morphological information by fMRU has to be emphasized. Regarding kidney function estimation preliminary results are encouraging.

Zusammenfassung

Hintergrund:

Analyse des Einflusses der funktionellen Magnetresonanz-Urografie (fMRU) auf das Therapiemanagement bei Kindern mit komplexer obstruktiver Uropathie im Vergleich zum konventionellen diagnostischen Algorithmus [KDA, Ultraschall, Nierensequenzszintigrafie (NSS)]

Patienten und Methoden:

Retrospektive Analyse von 10 pädiatrischen Patienten mit obstruktiver Uropathie [weiblich, n=3; männlich, n=7; Alter, 10,7 (2–17) Monate]. Die Patienten wurden gemäß dem KDA untersucht. Bei uneindeutigen Ergebnissen des KDA wurde zusätzlich eine fMRU-Untersuchung durchgeführt. Die seitengetrennte Nierenfunktion wurde mittels NSS und fMRU ermittelt und einander gegenübergestellt. Die Befunde wurden einem interdisziplinären Truth-Panel in einem 2-stufigen Entscheidungsprozess zur Verfügung gestellt (mit und ohne fMRU).

Ergebnisse:

Gemäß KDA wurde durch das Truth-Panel bei 8 Patienten eine chirurgische und in 2 Patienten eine konservative Therapie vorgeschlagen. Die Informationen aus der fMRU änderten die Therapiestrategie bei 3 Patienten und führten bei 8 Patienten zu einer Modifikation der initial gewählten chirurgischen Herangehensweise. Der Vergleich der seitengetrennten Nierenfunktion aus NSS und fMRU zeigte bei 7 Patienten konkordante und bei 2 Patienten diskordante (Differenz > 5%) Werte. In einem Fall war ein Vergleich nicht möglich.

Schlussfolgerung:

Die fMRU hat das Potenzial, das therapeutische Management einer obstruktiven Uropathie im Kindesalter zu verbessern. Im Falle einer chirurgischen Behandlung müssen vor allem die detaillierten morphologischen Informationen, die die fMRU zur Verfügung stellt, berücksichtigt werden. Bezüglich der Abschätzung der seitengetrennten Nierenfunktion sind diese initialen Ergebnisse ermutigend.

Key words

functional MR-Urography - radioisotope nephrography - obstructive uropathy - infants

Schlüsselwörter

funktionelle MR-Urografie - Nierensequenzszintigrafie - obstruktive Uropathie - Kleinkind

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