views. These views can also form a composite 3D view. Since breast vasculature is arranged radially, the vessels are enlarged in a parallel view, but become narrow in a perpendicular view. An inverse factor is applied to the image so that the high vasculature areas appear white on the image while the black areas are relatively avascular segments. Benign lesions and implants are usually not visualized. Two reconstruction modes are offered with CTLM: Front to Back Reconstruction and Maximal Intensity Projection. These two modes are used to evaluate the vascularization patterns to determine whether the images have normal or abnormal vascularization. Also, because tumor neovasculature is not limited to the tumor's anatomical border, CTLM will also reveal all recruited arteries and areas of increased circulation. This is an advantage to identify very small tumors. Clinical Trial Dr. Eric Milne conducted a small localized studying using CTLM as an adjunct to mammography, and he discovered that out of 122 cases, the number of biopsies required reduced from 89 to 47. Additionally, the sensitivity of CTLM is equal to mammography, but has much greater specificity. Devices Imaging Diagnostic Systems is a Florida-based company that has created a CTLM imaging device. However, in 2011 it was classified as a Class III medical device, and it is still undergoing approval. Comparison with other modalities CTLM has uses a near infrared laser of wavelength ~808 nm which is not impeded by the dense breast tissue. The sensitivity of mammography, CTLM and mammography+CTLM was 34.4%, 74.4% and 81.57% respectively among extremely dense breasts and 68.29%, 85.00% and 95.34% respectively among heterogeneously dense breasts. The combination of CTLM and mammography is able to distinguish between benign and malignant tumors with higher accuracy. Advantages It does not use ionizing radiation like in the case of Mammography, SPECT. It has higher sensitivity and specificity for imaging dense breast tissue. It does not require contrast agent unlike MRI. Patient discomfort is minimised. No breast compression is required. It is easy and inexpensive to operate. Disadvantages Radiologist requires specific skills to interpret and distinguish blood vessels in the CTLM images which is time consuming and complicated due to various shape of angiogenesis. This technology is awaiting FDA approval. See also Diffuse optical imaging Near-infrared window in biological tissue Diffuse optical mammography References Further reading CTLM-section on Imaging Diagnostic Systems website CTLM on Google Scholar Grable R.J. et al., Optical computed tomography