This disclosure provides systems and methods for measuring fluid flow in a vasculature system of a patient. Some systems may include an injection system configured to inject a bolus of fluid into a vessel of a patient. Some systems may include a measurement engine configured to monitor the bolus of fluid in the vessel using measurement data generated by an intravascular measuring device. The measurement engine may determine a travel distance of the bolus of fluid and an elapsed time during which the bolus of fluid traversed the travel distance based on the measurement data. A fluid flow rate (e.g., velocity, volumetric flow) of the vessel may be calculated using the travel distance and the elapsed time.