Abnormal microvascular function and angiogenesis are key components of various diseases that can contribute to
the perpetuation of the disease. Several skin diseases and ophthalmic pathologies are characterized by
hypervascularity, and in cancer the microvasculature of tumors is structurally and functionally abnormal. Thus, the
microvasculature can be an important target for treatment of diseases characterized by abnormal microvasculature.
Motivated largely by cancer research, significant effort has been devoted to research on drugs that target the
microvasculature. Several vascular targeting drugs for cancer therapy are in clinical trials and approved for clinical
use, and several off-label uses of these drugs have been reported for non-cancer diseases. The ability to image and
measure parameters related to microvessel function preclinically in laboratory animals can be useful for
development and comparison of vascular targeting drugs. For example, blood supply time measurements give
information related to microvessel morphology and can be measured with first-pass fluorescence imaging.
Hemoglobin saturation measurements give an indication of microvessel oxygen transport and can be measured with
spectral imaging. While each measurement individually gives some information regarding microvessel function, the
measurements together may yield even more information since theoretically microvessel morphology can influence
microvessel oxygenation, especially in metabolically active tissue like tumors. However, these measurements have
not yet been combined. In this study, we report the combination of blood supply time imaging and hemoglobin
saturation imaging of microvessel networks in tumors using widefield fluorescence and spectral imaging,
respectively. The correlation between the measurements in a mouse mammary tumor is analyzed.
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