We present a computational model for trans-vascular oxygen transport in synthetic tumor and host tissue blood vessel networks, aiming at qualitatively explaining published data of optical mammography, which were obtained from 87 breast cancer patients. The data generally show average hemoglobin concentration to be higher in tumors versus host tissue whereas average oxy-to total hemoglobin concentration (vascular segment RBC-volume-weighted blood oxygenation) can be above or below normal. Starting from a synthetic arterio-venous initial network the tumor vasculature was generated by processes involving cooption, angiogenesis, and vessel regression.
View Article and Find Full Text PDFDiffuse optical imaging and spectroscopy of the female breast is an area of active research. We review the present status of this field and discuss the broad range of methodologies and applications. Starting with a brief overview on breast physiology, the remodeling of vasculature and extracellular matrix caused by solid tumors is highlighted that is relevant for contrast in optical imaging.
View Article and Find Full Text PDFBackground: Patients with long-standing ulcerative colitis require repeated endoscopies for early detection of neoplasias, which, however, are frequently missed by standard colonoscopy. Fluorescence-guided colonoscopy is known to improve the detection rate but the long-term effects of fluorescence-guided colonoscopy are unknown.
Methods: Colitis patients with negative findings at index fluorescence-guided colonoscopy entered a prospective long-term study with conventional colonoscopies at 2-year intervals.
We present a scanning time-domain fluorescence mammograph capable to image the distribution of a fluorescent contrast agent within a female breast, slightly compressed between two parallel glass plates, with high sensitivity. Fluorescence of the contrast agent is excited using a near infrared picosecond diode laser module. Four additional picosecond diode lasers with emission wavelengths between 660 and 1066 nm allow to measure the intrinsic optical properties of the breast tissue.
View Article and Find Full Text PDFPurpose: To assess early- and late-fluorescence near-infrared imaging, corresponding to the vascular (early-fluorescence) and extravascular (late-fluorescence) phases of indocyanine green (ICG) enhancement, for breast cancer detection and benign versus malignant breast lesion differentiation.
Materials And Methods: The study was approved by the ethical review board; all participants provided written informed consent. Twenty women with 21 breast lesions were examined with near-infrared imaging before, during, and after intravenous injection of ICG.