propagation through the tissue to assess its optical properties. It is based on two basic principles: different tissue components have unique scattering and absorption characteristics for each wavelength and the malignant tumor growth requires neovascularization to grow beyond 2 mm in size. In new forming tumors, the blood flow increases and the CTLM then looks for high hemoglobin concentration (angiogenesis) in the breast that are structurally and functionally abnormal, and to detect neovascularization, which may be hidden in mammography images especially in dense breast. This neovascularization, which results in a greater volume of hemoglobin in a confined area, can be visualized using absorption measurements of laser light. Malignant lesions will be detected based on their higher optical attenuation compared to the surrounding tissue, which is mainly related to the increase in light absorption by their higher hemoglobin content. The CTLM device uses a laser diode than emits laser light at an 808 nm wavelength in the NIR spectrum that matches the crossover point of strong absorption of both oxygenated and deoxygenated hemoglobin. At this wavelength, water, fat, and skin can only weakly absorb light, having little effect on data acquisition. The 808 nm laser beam can penetrate breast tissue of any density, and thus can work equally well in the examination and imaging of extremely dense and heterogeneous breast tissue. CTLM looks for the areas of high absorption, where there is a high hemoglobin concentration indicating rich network of blood vessels, or angiogenesis. The area of angiogenesis is generally much larger than the tumor itself, and hence CTLM can detect small tumors that are sometimes invisible if using other imaging modalities, such as mammogram. However, the dispersion of photons in the tissue, although safe, can create a problem in the prediction of the path of the light in the tissue due to scattering. To solve this problem, CTLM system uses a large number of source and detector positions to take into account the diffusion approximation of light propagation in tissue, and to show the location of the increased vascularity in the breast. The data acquisition of CTLM is very similar to standard CT. The major difference is that CTLM uses near-infrared light, not X-ray, to produce the images. The patient lies on a padded table in the prone position with one breast suspended in the scanning chamber with nothing in contact with the pendant breast. The breast is surrounded by