A numerical study on the influence of vulnerable plaque composition on intravascular thermography measurements

Intracoronary thermography is a technique that measures lumen wall temperatures for vulnerable plaque detection. In this paper the influence of vulnerable plaque composition on lumen wall temperatures was studied numerically. Concerning the vulnerable plaque heat generation, the location of the heat source and its heat production were varied. Concerning the heat transfer, the thermal properties of the lipid core and the location of the vasa vasorum were studied. The heat source location was the main determinant of the lumen wall temperature distribution. The strongest effect was noted when the heat producing macrophages were located in the shoulder region leading to focal spots of higher temperature. The maximal lumen wall temperature was mainly determined by the heat production of the macrophages and the cooling effect of blood. The insulating properties of the lipid core increased lumen wall temperatures when the heat source was located in the cap and the presence of vasa vasorum lowered the temperatures. These results show that the lumen wall temperature distribution is influenced by vulnerable plaque composition and that intracoronary thermography techniques require a high spatial resolution. To be able to couple temperature measurements to plaque vulnerability, intracoronary thermography needs to be combined with an imaging modality.