Multispectral near-infrared tomography: a case study in compensating for water and lipid content in hemoglobin imaging of the breast

Images of hemoglobin concentration and oxygen saturation are presented from multispectral near-infrared tomographic measurements in the breast of a woman with an invasive cancer. Images of the absorption coefficient and reduced scattering coefficient are recovered from the measured data using a finite element reconstruction algorithm based on the frequency-domain diffusion equation. Three methods of recovering the hemoglobin concentration and oxygen saturation images are presented which compensate for water and lipid absorption in different ways: (1) an assumed bulk content of water and lipids is used, (2) four chromophores are imaged, and (3) scattering power data are applied to deduce water and lipid images. In all three cases, a large increase in the hemoglobin concentration (3:1) is observed at the location of the cancer while a maximum of 15 difference is observed in the hemoglobin images between each of these methods for water and lipid compensation. ©