Spatiotemporal Accuracy of Real-Time 3D Echocardiography in the Neonatal and Pediatric Setting – Validation Studies using Small Dynamic Test Objects

Abstract

The precision of real-time 3D-echocardiography (RT3DE) is not sufficiently validated for small, fast-moving structures such as the neonatal and pediatric heart.

Purpose: To assess the spatiotemporal accuracy of RT3DE in small, moving test objects.

Materials and Methods: Small, calibrated test objects in the size of neonatal and pediatric heart chambers were made from polyurethane foam or metal wire mesh and moved in a water bath through a calibrated dynamic test system. Using matrix transducers (X7-2, ie33 and X4-1, Sonos 7500, Philips, Andover, USA), 2 D and live 3 D datasets under variation of the motion speed (0.033 – 0.133 m/s corresponding to 50 – 200 heart cycles/minute), the volume rate and transducer position were recorded and analyzed (QLab 7.0, Philips).

Results: 3 D datasets of the moving test objects showed relevant spatial distortion, which was obviously related to the sequential scanning technology of the matrix transducer. Different segments of a test object were not recorded simultaneously, but rather row-by-row, so that there was a time delay between the first and the last-recorded voxel of a single 3 D volume (mean±SD: 28.9 ± 7.82 m/s or 80 ± 7 % of the time duration of a 3 D volume). With increasing motion speed of the test object and reduced 3 D volume rate, the distortion artifacts increased significantly.

Conclusion: 3 D acquisitions using matrix technology demonstrate relevant spatiotemporal inaccuracies. This may lead to misinterpretations during the evaluation of the synchronicity of valvular or ventricular motion and incorrect definition of volume estimations. In particular, at higher heart rates and higher rates of movement, these limitations have to be taken into account in clinical practice.

Zusammenfassung

Die Präzision der Real-Time-3D-Echokardiografie (RT3DE) ist für kleine, sich schnell bewegende Strukturen wie neonatale und kindliche Herzen nicht ausreichend validiert.

Ziel: Überprüfung der zeitlichen Genauigkeit der RT3DE an kleinen, bewegten Testobjekten.

Material und Methoden: Kleine, definierte Testobjekte in Größe neonataler und kindlicher Herzkammern wurden im Wasserbad durch ein kalibriertes dynamisches Testsystem bewegt. 2D- und live-3D-Datensätze wurden mit Matrix-Schallköpfen (X7-2, ie33 und X4-1, Sonos 7500, Philips, Andover, USA) unter Variation der Bewegungsgeschwindigkeit (0,033 – 0,133 m/s entsprechend 50 – 200 Herzzyklen/min.), Bildrate und Position des Ultraschallkopfes aufgenommen und ausgewertet (QLab 7.0, Philips).

Ergebnisse: Die 3D-Datensätze von bewegten Testobjekten wiesen eine relevante räumliche Verzerrung auf, die durch die sequentielle Aufnahmetechnik des Matrix-Ultraschallkopfes bedingt war. Verschiedene Segmente eines Testobjektes werden zeilenweise nacheinander aufgenommen, sodass eine zeitliche Latenz zwischen dem ersten und dem letzten aufgenommenen Voxel eines 3D-Volumens entsteht (im Mittel 28,9 ± 7,82 m/s bzw. 80 ± 7 % der Dauer eines 3D-Volumens). Mit zunehmender Geschwindigkeit des bewegten Objektes und verminderter Bildrate nahmen die Distorsionsartefakte zu.

Schlussfolgerungen: 3D-Aufnahmen mittels Matrixtechnologie weisen relevante zeitliche Unschärfen auf. Bei der Beurteilung der Synchronizität von Klappen- oder Myokardbewegungen können diese zu Fehlinterpretationen führen. Insbesondere bei hohen Schlagfrequenzen und hohen Bewegungsgeschwindigkeiten müssen diese Limitationen in der klinischen Anwendung berücksichtigt werden.

Key words

real-time 3D-echocardiography - spatiotemporal accuracy - children - matrix transducer - congenital heart disease

• References

• 1 Lopez L, Colan SD, Frommelt PC et al. Recommendations for quantification methods during the performance of a pediatric echocardiogram: a report from the Pediatric Measurements Writing Group of the American Society of Echocardiography Pediatric and Congenital Heart Disease Council. J Am Soc Echocardiogr 2010; 23: 465-495
• 2 Kollmann C, de Korte C, Dudley NJ et al. Guideline for Technical Quality Assurance (TQA) of ultrasound devices (B-Mode)--version 1.0 (July 2012): EFSUMB Technical Quality Assurance Group-US-TQA/B. Ultraschall in Med 2012; 33: 544-549
• 3 Lang RM, Badano LP, Tsang W et al. EAE/ASE recommendations for image acquisition and display using three-dimensional echocardiography. J Am Soc Echocardiogr 2012; 25: 3-46
• 4 Herberg U, Lück S, Steinweg B et al. Volumetry of fetal hearts using 3D real-time matrix echocardiography – in vitro validation experiments and 3D echocardiographic studies in fetuses. Ultraschall in Med 2011; 32: 46-53
• 5 Yang HS, Bansal RC, Mookadam F et al. Practical guide for three-dimensional transthoracic echocardiography using a fully sampled matrix array transducer. J Am Soc Echocardiogr 2008; 21: 979-989
• 6 Trier HG, Herberg U. A dynamic test system for simulating fetal cardiac phases and for testing time resolution and volumetry in 2D and 3D echocardiography. In: Trier HG, Hahn R, Herberg U, (eds.) 2D/3D echocardiography of the fetal and infantile heart: Approaches for the analysis of equipment performance. Bonn: TIMUG eV; 2011: 13-44
• 7 Faller J, Klebach C, Trier HG et al. Construction of a pulsatile echophantom which can be used for validation of volumetry with 3D-realtime-echocardiography (RT-3DE). Ultrasound Med Biol 2011; 37: p48
• 8 Satrapa J, Schultz HJ, Doblhoff G. Automated quality control of ultrasonic B-mode scanners by applying an TMM 3D cyst phantom. Ultraschall in Med 2006; 27: 262-272
• 9 Herberg U, Brand M, Bernhardt C et al. Variables influencing the accuracy of 2-dimensional and real-time 3-dimensional echocardiography for assessment of small volumes, areas, and distances: an in vitro study using static tissue-mimicking phantoms. J Ultrasound Med 2011; 30: 899-908
• 10 Del Grosso VA, Mader CW. Speed of Sound in Pure Water. J Acoust Soc Am 1972; 52: 1442-1446
• 11 Herberg U, Berg C, Knöpfle G et al. Intrapericardial teratoma in the newborn--3D-echocardiography and course of disease. Ultraschall in Med 2006; 27: 577-581
• 12 Bland JM, Altman DG. Applying the right statistics: analyses of measurement studies. Ultrasound Obstet Gynecol 2003; 22: 85-93
• 13 Leung KYE, Bosch JG. Automated border detection in three-dimensional echocardiography: principles and promises. Eur J Echocardiogr 2010; 11: 97-108
• 14 Mor-Avi V, Lang RM. The evolution of three-dimensional echocardiography – How did it happen. In: Badano LP, Lang RM, Zamorano JL, (eds.) Textbook of Real-Time Three Dimensional Echocardiography. London: Springer; 2011: 1-8
• 15 Schindera ST, Mehwald PS, Sahn DJ et al. Accuracy of real-time three-dimensional echocardiography for quantifying right ventricular volume: static and pulsatile flow studies in an anatomic in vitro model. J Ultrasound Med 2002; 21: 1069-1075
• 16 Hagendorff A, Stöbe S, Tarr A et al. Special echocardiographic diagnosis and specific problem constellations in patients with degenerative stenosis of the aortic valve. Ultraschall in Med 2013 34: 214-232
• 17 Dorosz JL, Lezotte DC, Weitzenkamp DA et al. Performance of 3-dimensional echocardiography in measuring left ventricular volumes and ejection fraction: a systematic review and meta-analysis. J Am Coll Cardiol 2012; 59: 1799-1808
• 18 Shimada YJ, Shiota M, Siegel RJ et al. Accuracy of right ventricular volumes and function determined by three-dimensional echocardiography in comparison with magnetic resonance imaging: a meta-analysis study. J Am Soc Echocardiogr 2010; 23: 943-953
• 19 Greupner J, Zimmermann E, Grohmann A et al. Head-to-head comparison of left ventricular function assessment with 64-row computed tomography, biplane left cineventriculography, and both 2- and 3-dimensional transthoracic echocardiography: comparison with magnetic resonance imaging as the reference standard. J Am Coll Cardiol 2012; 59: 1897-1907
• 20 Mor-Avi V, Sugeng L, Lang RM. Real-time 3-dimensional echocardiography: an integral component of the routine echocardiographic examination in adult patients?. Circulation 2009; 119: 314-329
• 21 Friedberg MK, Su X, Tworetzky W et al. Validation of 3D echocardiographic assessment of left ventricular volumes, mass, and ejection fraction in neonates and infants with congenital heart disease: a comparison study with cardiac MRI. Circ Cardiovasc Imaging 2010; 3: 735-742
• 22 Simpson JM. Real-time three-dimensional echocardiography of congenital heart disease using a high frequency paediatric matrix transducer. Eur J Echocardiogr 2008; 9: 222-224
• 23 Jasaityte R, Heyde B, D’hooge J. Current state of three-dimensional myocardial strain estimation using echocardiography. J Am Soc Echocardiogr 2013; 26: 15-28
• 24 Nii M, Roman KS, Macgowan CK et al. Insight into normal mitral and tricuspid annular dynamics in pediatrics: a real-time three-dimensional echocardiographic study. J Am Soc Echocardiogr 2005; 18: 805-814
• 25 Herberg U, Steinweg B, Berg C et al. Echocardiography in the fetus – a systematic comparative analysis of standard cardiac views with 2D, 3D reconstructive and 3D real-time echocardiography. Ultraschall in Med 2011; 32: 293-301
• 26 Faller J, Klebach C, Breuer J et al. How accurate is 3D-realtime-echocardiography (RT-3DE) for recording the time flow of a cardiac cycle? A study using controller-operated pulsative phantoms. Ultrasound Med Biol 2011; 37: p49
• 27 Herberg U, Faller J, Klebach C et al. Überprüfung des zeitlichen Ablaufes von 3D-echokardiografischen Volumenmessungen durch ein pulsatiles Phantom. Ultraschall in Med 2010; 31: 11