Exploring the Complexity of Cardiac Motion by Multiscale Motion Mapping
P. Hunziker, M. Sühling, M. Arigovindan, C.H.P. Jansen, A. Linka, P. Buser, S. Marsch, M. Unser
Menarini prize for echocardiography of the Working Group for Echocardiography of the Swiss Society of Cardiology, Actes de l'assemblée annuelle commune, Société Suisse de Cardiologie, Société Suisse de Chirurgie Thoracique et Cardio-Vasculaire, Société Suisse de Médecine Intensive, Lausanne VD, Swiss Confederation, May 8-10, 2003, vol. 6, supp. 5, pp. 17 S.
Menarini Prize for Echocardiography of the Working Group for Echocardiography of the Swiss Society of Cardiology.
Background: Measuring motion is fundamental for echo. Conventionally, this is done by «eyeballing», i.e. visual inspection, with strong intraobserver variability. More recently, tissue Doppler echo and border detection algorithms have been introduced, but their limited impact on routine echo reflects some of their weaknesses, including a limitation to strict 1D motion vectors and the angle dependence of Doppler.
Methods/Results: Multiscale Motion Mapping is a novel echo technique developed in Switzerland with support of the Swiss Heart Foundation and the National Research Foundation. This technique is able to assess cardiac motion at arbitrary locations in the echocardiogram, based on exhaustive mathematical analysis of the images using so-called «optical flow techniques», spline-based imaging, and hierarchical image decomposition. After successful testing of this technique in synthetic echocardiograms constructed to contain defined motion patterns, and in a physical phantom of heart motion, we explored its potential in clinical echocardiograms.
The ability to display motion independent of the ultrasound beam angle was assessed in the short axis views of the left ventricle. We found that the resulting color motion map showed systolic inward- and diastolic outward motion at all locations of the short axis view, in strong contrast to tissue Doppler that failed to show motion at 90 and 270 degrees of the short axis circle.
The ability of Multiscale Motion Mapping to analyze complex 2D motion was tested in short axis views using a novel vector motion display: in this case, apical rotation/twisting could clearly be shown, a phenomenon otherwise difficult to observe in echo. Complex motion patterns of the mitral anulus became also evident when examining apical views in the so-called «needle» display (figure): here we found vortex-like motion patterns of the annulus with opposite rotation directions in the septal and lateral annulus in normal patients, and disruption of this pattern in patients with ischemic heart disease.
Conclusion: Multiscale Motion Mapping, a novel method for objective and quantitative determination of myocardial motion, has been validated in vitro and is applicable to clinical echocardiograms. Its unprecedented ability to measure full 2D motion patterns at arbitrary locations in the echo opens a new window to the complexity of cardiac motion in health and disease, and highlights the limitations of current «quantitative» methods.
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AUTHOR="Hunziker, P. and S{\"{u}}hling, M. and Arigovindan, M. and
Jansen, C.H.P. and Linka, A. and Buser, P. and Marsch, S. and Unser,
M.",
TITLE="Exploring the Complexity of Cardiac Motion by Multiscale Motion
Mapping",
BOOKTITLE="Actes de l'assembl{\'{e}}e annuelle commune,
Soci{\'{e}}t{\'{e}} Suisse de Cardiologie, Soci{\'{e}}t{\'{e}}
Suisse de Chirurgie Thoracique et Cardio-Vasculaire,
Soci{\'{e}}t{\'{e}} Suisse de M{\'{e}}decine Intensive",
YEAR="2003",
editor="",
volume="6, supp. 5",
series="",
pages="17 S",
address="Lausanne VD, Swiss Confederation",
month="May 8-10,",
organization="",
publisher="",
note="Menarini prize for echocardiography of the Working Group for
Echocardiography of the Swiss Society of Cardiology")