Assessing the spatial extent of breast tumor intrinsic optical contrast using ultrasound and diffuse optical spectroscopy

• Published in: Journal of Biomedical Optics 2008-05, Vol.13 (3), p.030504-030503
• Main Authors: Li, Ang, Liu, Jing, Tanamai, Wendy, Kwong, Richard, Cerussi, Albert E, Tromberg, Bruce J
• Format: Article
• Language: English
• Subjects: Adult; Biomarkers, Tumor - analysis; Breast; breast cancer; Breast Neoplasms - diagnostic imaging; Breast Neoplasms - metabolism; Computer simulation; diffuse optical imaging (DOI); Female; Finite element method; Humans; Image Interpretation, Computer-Assisted - methods; Mathematical models; near infrared; photon migration; Reflectance; Spectrum Analysis - methods; Tissue Distribution; Tumors; Ultrasonography, Mammary - methods; Ultrasound
• ISSN: 1083-3668; 1560-2281
• DOI: 10.1117/1.2937471

Little is known about the relationship between anatomic and functional contrast derived from intrinsic optical signals. In order to address this relationship, finite-element (FEM) forward simulations were compared to diffuse optical spectroscopy (DOS) reflectance measurements obtained from 10 breast tumor patients. Clinical ultrasound images were used to estimate anatomical tumor size and depth for the FEM simulations. Actual DOS-measured tumor absorption could not be matched by forward model simulations when tumor size was constrained to match ultrasound dimensions. However, agreement was achieved when the lesion was viewed as a distribution of optical properties (i.e., an extended target). This result suggests that the spatial extent of optical contrast in breast tumors may be significantly greater than anatomical dimensions reported by standard imaging modalities. Analysis indicates that invasive breast tumors with anatomical dimensions of may still be detectable at depths of or more (the center of the lesion to the surface of tissue) using DOS in a reflectance geometry.