Department of Medical Physics, School of Medicine, University of Patras, GR26500 Patras, Greece. imarazi@heart.med.upatras.gr|Department of Medical Physics, School of Medicine, University of Patras, GR26500 Patras, Greece. imarazi@heart.med.upatras.gr|Department of Medical Physics, School of Medicine, University of Patras, GR26500 Patras, Greece. imarazi@heart.med.upatras.gr