Abstract: An apparatus including: an imaging system; a probe for insertion into a vessel, the probe being coupled to the imaging system; a flow delivery system associated with the probe to release a differential-contrast fluid into the vessel at a location proximal to an end of the probe; and a processor to: collect data from the imaging system based on release of the differential-contrast fluid into the vessel, analyze the collected data to identify a presence or absence of the differential-contrast fluid as a function of time, and determine a flow rate in the vessel based on analyzing the collected data.

Abstract: According to an exemplary embodiment of the present disclosure, an apparatus can be provided which can include at least one first arrangement providing a radiation, and including a splitter structure separating the radiation into at least one first electro-magnetic radiation directed to a sample and at least one second electro-magnetic radiation directed to a reference. A frequency of the radiation provided by the first arrangement can be varied over time by the first arrangement. The apparatus can also include at least one detector second arrangement configured to detect a first interference and a second interference between at least one third radiation associated with the first radiation(s) and at least one fourth radiation associated with the second radiation(s), whereas the first and second interferences can be different from one another.