B-Flow Sonography vs. Color Doppler Sonography for the Assessment of Vascularity in Pediatric Kidney Transplantation

Elena Dammann; Michael Groth; Raphael-Sebastian Schild; Anja Lemke; Jun Oh; Gerhard Adam; Jochen Herrmann

doi:10.1055/a-1167-8317

RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, Table of Contents

Rofo 2021; 193(01): 49-60
DOI: 10.1055/a-1167-8317

Pediatric Radiology

B-Flow Sonography vs. Color Doppler Sonography for the Assessment of Vascularity in Pediatric Kidney Transplantation

B-Flow-Sonografie im Vergleich mit Color-Doppler-Sonografie zur Evaluation der Gefäßversorgung transplantierter Nieren im Kindesalter

Authors

Elena Dammann

¹Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Michael Groth

²Section of Pediatric Radiology, Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Raphael-Sebastian Schild

³Department of Pediatric Nephrology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Anja Lemke

³Department of Pediatric Nephrology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Jun Oh

³Department of Pediatric Nephrology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Gerhard Adam

¹Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Jochen Herrmann

²Section of Pediatric Radiology, Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany

Abstract

Objective To compare B-flow sonography (BFS) with color Doppler sonography (CDS) for imaging of kidney transplant vascularization in children.

Patients and Methods All children receiving a kidney transplantation who underwent a protocol-based ultrasound examination (Loqiq 9, GE Medical Systems, Milwaukee, WI, USA) using the BFS and CDS technique with equal settings and probe position between January 2013 and January 2016 were retrospectively assessed (n = 40). The obtained datasets were visually graded according to the following criteria: (I) delineation of the renal vascular tree (Grade 1 – clear demarcation of interlobar, together with arcuate and interlobular vessels; Grade 2 – clear demarcation of interlobar and cortical vessels, but no distinction of interlobular from arcuate vessels; Grade 3 – only clear demarcation of interlobar vessels, Grade 4 – insufficient demarcation) (II) delineation of cortical vessel density in ventral, lateral, and dorsal part of the transplant, (III) smallest vessel-capsule distance, and (IV) maximum cortical vessel count. Comparison between methods was performed using Fisher’s exact and paired sample t-tests.

Results Applying a curved transducer (C1–6), BFS showed superior delineation of the renal vascular tree (p < 0.001), a lower vessel-capsule distance (p < 0.001), a higher cortical vessel count (p < 0.001), and a higher cortical vessel density in the superficial cortex (p = 0.01) than CDS. In the dorsal and lateral aspects of the transplant, cortical vessel density was lower with BFS (both p < 0.001). Using a linear high-resolution transducer (ML 6–15), no significant differences between the methods were found.

Conclusion Improved imaging of kidney transplant vascularization can be achieved in children by adding BFS to a standard protocol. The BFS technique is especially beneficial for overall assessment of the renal vascular tree together with the extent of cortical vascularization on curved array images.

Key points:

Depiction of vascular tree and ventral cortical vessels is improved by BFS.
The dorso-lateral cortex was better represented with CDS because of higher penetration.
Additional monitoring with BFS improves the monitoring of transplant viability.

Citation Format

Dammann E, Groth M, Schild R et al. B-Flow Sonography vs. Color Doppler Sonography for the Assessment of Vascularity in Pediatric Kidney Transplantation. Fortschr Röntgenstr 2021; 193: 49 – 60

Zusammenfassung

Ziel Die Beurteilung der Gefäßversorgung transplantierter Nieren im Kindesalter mittels B-Flow-Sonografie (BFS) im Vergleich zur Color-Doppler-Sonografie (CDS).

Patienten und Methoden Alle Kinder nach Nierentransplantation, die im Zeitraum von Januar 2013 bis Januar 2016 in unserer Klinik eine protokollbasierte Ultraschalluntersuchung in BFS- und CDS-Technik mit identischen Grundeinstellungen erhielten (Loqiq 9, GE Medical Systems, Milwaukee, WI, USA), wurden retrospektiv evaluiert (n = 40). Die erhaltenen Bilddaten wurden visuell klassifiziert: (I.) Darstellung des gesamten renalen Gefäßbaums (Grad 1 – interlobäre, arcuatae und interlobuläre Gefäße abgrenzbar; Grad 2 – interlobäre und kortikale Gefäße abgrenzbar, nicht arcuatae von interlobulären Gefäßen abgrenzbar; Grad 3 – nur interlobäre Gefäße abgrenzbar; Grad 4 – insuffiziente Abgrenzbarkeit), (II.) Dichte der Kortexgefäße im ventralen, lateralen und dorsalen Nierenanteil, (III.) geringster Gefäß-Kapsel-Abstand und (IV.) maximale Anzahl von Kortexgefäßen. Der statistische Vergleich erfolgte mittels exaktem Fisher-Test und gepaartem T-Test.

Ergebnisse Unter Verwendung eines Sektorschallkopfes (C1–6) zeigte BFS im Vergleich mit CDS eine vollständigere Darstellung des renalen Gefäßbaums (p < 0,001) mit einem geringeren Gefäß-Kapsel-Abstand (p < 0,001) und einer höheren maximalen Gefäßdichte im ventralen Kortex (p < 0,001) mit einer höheren max. Anzahl von Gefäßen (p = 0,01). Im dorsalen und lateralen Transplantatanteil war die nachweisbare Gefäßdichte niedriger mit BFS als mit CDS (jeweils p < 0,001). Unter Verwendung eines hochauflösenden Linearschallkopfes (ML 6–15) konnte kein Unterschied zwischen BFS und CDS nachgewiesen werden.

Schlussfolgerung Eine verbesserte Darstellung des Vaskularisationsgrades von Nierentransplantaten im Kindesalter kann erreicht werden, indem BFS zum Standardprotokoll hinzugefügt wird. Die BFS zeigt insbesondere Vorteile in der Erfassung des renalen Gefäßbaums und der Charakterisierung der schallkopfnahen Kortexgefäße unter Verwendung eines Konvexschallkopfes

Kernaussagen:

BFS verbessert die Darstellung des Gefäßbaums und der schallkopfnahen Kortexregion in Nierentransplantaten.
Im dorsolateralen Kortex ist die Gefäßdarstellung mit CDS aufgrund besserer Penetration günstiger.
Die Ergänzung eines Standardprotokolls mit BFS erlaubt ein qualitativ verbessertes Transplantatmonitoring.

Key words

ultrasonography - doppler - color - kidney transplantation - child

Full Text

References

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