Use of components analysis to identify internal heat in breast dynamic thermal images
preprintposted on 28.06.2021, 16:45 by Meir Gershenson
I suggest a method for biomedical imaging with heat using principal and independent components analysis. This method produces novel results suggesting physiologic mechanisms. When using thermal imaging to detect breast cancer, the dominant heat signature is of indirect heat transported by the blood away from the tumor location into the skin. Interpretation is usually based on vascular patterns and not by observing the direct cancerous heat. In this new method one uses a sequence of thermal images of the patient’s breast following external temperature change. Data are recorded and analyzed using independent component analysis (ICA) and principal component analysis (PCA). ICA separates the image sequence into new independent images having a common characteristic time behavior. Using the Brazilian visual lab mastology data set, I observed three types of component images: Images corresponding to a minimum change as a function of applied temperature or time, which suggests an association with the cancer generated heat, images in which a moderate temperature dependence is associated with veins affected by vasomodulation, and images of complex time behavior indicating heat absorption due to high perfusion of the tumor. All components appear to clearly and distinctly represent underlying physiology.