Science and engineering of medical imaging [electronic resource] : ECO2 : proceedings : 24-26 April 1989, Paris, France / Max A. Viergever, chair/editor ; the Congress of EPS--European Physical Society, Europtica--the European Federation for Applied Optics, SPIE--the International Society for Optical Engineering ; cooperating organizations, ANRT--Association Nationale de la Recherche Technique [and others]