Toward Robust Myocardial Blush Grade Estimation in Contrast Angiography Carlo Gatta 1 , Juan Diego Gomez Valencia 1 , Francesco Ciompi 1 , Oriol Rodriguez Leor 2 , and Petia Radeva 1 1 Computer Vision Center, Campus UAB, Edifici O, 08193, Bellaterra, Barcelona, Spain cgatta@cvc.uab.es 2 Unitatd’hemodin`amicacard´ ıaca hospital universitari Germans Trias i Pujol Badalona, Spain Abstract. The assessment of Myocardial Blush Grade after primary an- gioplasty is a precious diagnostic tool to understand if the patient needs further medication or the use of specifics drugs. Unfortunately, the assess- ment of MBG is difficult for non highly specialized staff. Experimental data show that there is poor correlation between MBG assessment of low and high specialized staff, thus reducing its applicability. This paper proposes a method able to achieve an objective measure of MBG, or a set of parameters that correlates with the MBG. The method tracks the blush area starting from just one single frame tagged by the physician. As a consequence, the blush area is kept isolated from contaminating phenomena such as diaphragm and arteries movements. We also present a method to extract four parameters that are expected to correlate with the MBG. Preliminary results show that the method is capable of ex- tracting interesting information regarding the behavior of the myocardial perfusion. Keywords: Medical Imaging, Tracking, Optical Flow, Myocardial per- fusion, Myocardial Blush Grade, Primary Angioplasty. 1 Introduction Primary angioplasty is the most effective way to re-establish a normal flow in an obstructed artery after an acute myocardial infarction. This medical intervention aims at recover a proper coronary flow into the obstructed artery. Physicians lo- calize the artery by visual inspection of a contrast angiography. However, even in a successful primary angioplasty, it can happen that an adequate irrigation on the area subtended by the affected artery is not optimal. In this area, the mi- crocirculation could be not sufficient even after a successful primary angioplasty, thus compromising in a serious way the long term patient survival [1]. The physicians are able to ascertain with enough precision if the normal flow in the unblocked artery has been really recovered by observing pre and post in- tervention angiographies. To do this, physicians inject a contrast liquid into the H. Araujo et al. (Eds.): IbPRIA 2009, LNCS 5524, pp. 249–256, 2009. c  Springer-Verlag Berlin Heidelberg 2009