Thermal Detection of Embedded Tumors Using Infrared  Imaging

Mital M, Scott EP.    Department of Mechanical Engineering, Virginia Tech,  Blacksburg, VA 24060

Breast cancer is the most common cancer among women.  Thermography, also known as thermal or infrared imaging, 
is a procedure to determine if an abnormality  is present in the breast tissue temperature  distribution. This abnormality 
in temperature  distribution might indicate the presence of an  embedded tumor. Although thermography is currently  
used to indicate the presence of an abnormality, there  are no standard procedures to interpret these and  determine 
the location of an embedded tumor. This  research is a first step towards this direction. It  explores the relationship 
between the characteristics  (location and power) of an embedded heat source and  the resulting temperature 
distribution on the surface.  Experiments were conducted using a resistance heater  that was embedded in agar in 
order to simulate the  heat produced by a tumor in the biological tissue. The  resulting temperature distribution on 
the surface was  imaged using an infrared camera. In order to estimate  the location and heat generation rate of the 
source  from these temperature distributions, a genetic  algorithm was used as the estimation method. The  genetic 
algorithm utilizes a finite difference scheme  for the direct solution of the Pennes bioheat  equation. It was determined 
that a genetic algorithm  based approach is well suited for the estimation  problem since both the depth and the heat 
generation  rate of the heat source were accurately predicted. 
PMID: 17227096 [PubMed - indexed for MEDLINE]