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Q: Quantenoptik

Q 38: Laser in Medicine

Q 38.4: Talk

Friday, April 6, 2001, 18:15–18:30, H 2013

Imaging of Breast Tumors Using a Scanning Laser Pulse Mammograph — •Dirk Grosenick¹, Heidrun Wabnitz¹, Rainer Macdonald¹, K. Thomas Moesta², Peter Schlag², and Herbert Rinneberg¹ — ¹Physikalisch-Technische Bundesanstalt, Abbestr.2-12, D-10587 Berlin — ²Robert-Rössle-Klinik, Humboldt-Universität Berlin, Lindenberger Weg 80, D-13125 Berlin

A time-domain optical mammograph was used to record optical mammograms of more than 30 patients at selected near-infrared wavelengths. Distributions of times of flight of photons transmitted through the breast were measured at 1000 to 2000 scan positions in craniocaudal and mediolateral projection. In the majority of cases tumors could be detected from two-dimensional mammograms displaying photon counts in selected time windows. At each scan position effective absorption and transport scattering coefficients were derived applying diffusion theory. At the location of the tumor an increased absorption was observed in most cases. From effective absorption coefficients at two wavelengths (785 nm, 670 nm) semi-quantitative maps of tissue oxygenation and of hemoglobin concentration were derived showing an increased blood volume at the location of the tumor. To obtain additional information about the position of the tumor along the direction of breast compression we measured distributions of times of flight of photons under different projection angles, i. e. for different offsets between source and detector fiber.