<International Circulation>:  Is OCT alone enough for identification of vulnerable plaque?  A combination of OCT and IVUS may be better， but could increase the cost significantly， so what do you think about the best strategy for identifying vulnerable plaques?

Prof. Guagliumi: We have wanted to have a single technique for identification of vulnerable plaque but we still do not have any technology that can identify vulnerable plaque because we still do not know the meaning of vulnerable plaque. We know that it is a combination of factors. An advantage of OCT is the unique technology that is able to measure cap thickness and it is the most promising in identification of the activating macrophages. Activating macrophages means inflammation when you have a thin cap plus inflammatory response at this level you have a dramatic increase in the possibility of a plaque rupture. Presently， we are still in the range to identify and measure cap thickness but there is already a lot of data in favor of the possibility to measure the amount of activating macrophages.