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

^* Both authors contributed equally.

• References

• 1 Abou El-Ghar ME, Shokeir AA, Refaie HF et al. MRI in patients with chronic obstructive uropathy and compromised renal function: a sole method for morphological and functional assessment. Br J Radiol 2008; 968: 624-629
• 2 Blandino A, Minutoli F, Gaeta M et al. MR pyelography in 115 patients with a dilated renal collecting system. Acta Radiol 2001; 5: 532-536
• 3 Caravan P, Ellison JJ, McMurry TJ et al. Gadolinium(III) Chelates as MRI Contrast Agents Structure, Dynamics, and Applications. Chemical reviews 1999; 9: 2293-2352
• 4 Chandrasekharam VV, Srinivas M, Bal CS et al. Functional outcome after pyeloplasty for unilateral symptomatic hydronephrosis. Pediatr Surg Int 2001; 17: 524-527
• 5 Garne E, Loane M, Wellesley D et al. Congenital hydronephrosis: prenatal diagnosis and epidemiology in Europe. J Pediatr Urol 2009; 1: 47-52
• 6 Gordon I, Piepsz A, Sixt R European Association of Nuclear Medicine (2011) EANM, Vienna. EANM Guidelines http://www.eanm.org/publications/guidelines/gl_paed_renogram_2011.pdf
• 7 Gordon I. Pediatric aspects of radionuclides in nephrourology. In: Murray ICP, Ell PJ. Nuclear medicine in clinical diagnosis and treatment. 2^nd ed. Churchill Livingstone; Edinburgh; London; New York: 1998
• 8 Grattan-Smith JD, Little SB, Jones RA. MR urography in children: how we do it. Pediatr Radiol 2008; 1: 3-17
• 9 Hahn G, Sorge I, Gruhn B et al. Pharmacokinetics and safety of gadobutrol-enhanced magnetic resonance imaging in pediatric patients. Invest Radiol 2009; 12: 776-783
• 10 Hohenfellner K, Seemayer S, Stolz G et al. Pre- and postpartum ultrasound examinations for diagnosis of urogenital abnormalities. Klin Padiatr 2000; 6: 320-325
• 11 Jones RA, Easley K, Little SB et al. Dynamic contrast-enhanced MR urography in the evaluation of pediatric hydronephrosis: Part 1, functional assessment. AJR Am J Roentgenol 2005; 185: 1598-1607
• 12 Khrichenko D, Darge K. Functional analysis in MR urography – made simple. Pediatr Radiol 2010; 40: 182-199
• 13 Lassmann M. The new EANM paediatric dosage card. Eur J Nucl Med Mol Imaging 2008; 9: 1748
• 14 McDaniel BB, Jones RA, Scherz H et al. Dynamic contrast-enhanced MR urography in the evaluation of pediatric hydronephrosis: Part 2, anatomic and functional assessment of uteropelvic junction obstruction. AJR Am J Roentgenol 2005; 185: 1608-1614
• 15 Mende T. Nuklearmedizinische nephrourologische Diagnostik – der Stellenwert in der klinischen Diagnostik. Z Gesamte Inn Med 1983; 19: 201-204
• 16 O’Reilly PH, Aurell M, Britton K et al. Consensus on diuresis renography for investigating the dilated upper urinary tract. Radionuclides in Nephrourology Group. Consensus Committee on Diuresis Renography. J Nucl Med 1996; 11: 1872-1876
• 17 O’Reilly PH. Obstructive uropathy. Q J Nucl Med 2002; 46: 295-303
• 18 Perez-Brayfield MR, Kirsch AJ, Jones RA et al. A prospective study comparing ultrasound, nuclear scintigraphy and dynamic contrast enhanced magnetic resonance imaging in the evaluation of hydronephrosis. J Urol 2003; 170: 1330-1334
• 19 Podevin G, Mandelbrot L, Vuillard E et al. Outcome of urological abnormalities prenatally diagnosed by ultrasound. Fetal Diagn Ther 1996; 3: 181-190
• 20 Prince MR, Zhang H, Morris M et al. Incidence of nephrogenic systemic fibrosis at two large medical centers. Radiology 2008; 3: 807-816
• 21 Riccabona M, Avni FE, Blickman JG et al. Imaging recommendations in paediatric uroradiology. Minutes of the ESPR uroradiology task force session on childhood obstructive uropathy, high-grade fetal hydronephrosis, childhood haematuria, and urolithiasis in childhood. ESPR Pediatr Radiol 2009; 8: 891-898
• 22 Riccabona M, Avni FE, Dacher JN et al. ESPR uroradiology task force and ESUR paediatric working group: imaging and procedural recommendations in paediatric uroradiology, part III. Minutes of the ESPR uroradiology task force minisymposium on intravenous urography, uro-CT and MR-urography in childhood. Pediatr Radiol 2010; 7: 1315-1320
• 23 Rißmann A, Hoyer-Schuschke J, Köhn A et al. Fehlbildungsmonitoring Sachsen-Anhalt (2009) Jahresbericht des Bundeslandes Sachsen-Anhalt zur Häufigkeit von congenitalen Fehlbildungen und Anomalien sowie genetisch bedingten Erkrankungen http://angeborene-fehlbildungen.com/images/stories/Bericht2009_WEB.pdf
• 24 Roarke MC, Sandler CM. Provocative imaging. Diuretic renography. Urol Clin North Am 1998; 2: 227-249
• 25 Rohrschneider WK, Becker K, Hoffend J et al. Combined static-dynamic MR urography for the simultaneous evaluation of morphology and function in urinary tract obstruction. II. Findings in experimentally induced ureteric stenosis. Pediatr Radiol 2000; 8: 523-532
• 26 Schwartz GJ, Haycock GB, Edelmann CM et al. A simple estimate of glomerular filtration rate in children derived from body length and plasma creatinine. Pediatrics 1976; 2: 259-263
• 27 Shokeir AA, El-Diasty T, Eassa W et al. Diagnosis of ureteral obstruction in patients with compromised renal function: the role of noninvasive imaging modalities. J Urol 2004; 1: 2303-2306
• 28 Wolf GL, Hoop B, Cannillo JA et al. Measurement of renal transit of gadopentetate dimeglumine with echo-planar MR imaging. J Magn Reson Imaging 1994; 3: 365-372
• 29 Zou Z, Zhang HL, Roditi GH et al. Nephrogenic systemic fibrosis: review of 370 biopsy-confirmed cases. JACC Cardiovasc Imaging 2011; 11: 1206-1216