Method and apparatus for imaging vascular activity dynamically at a microscopic scale

Method for imaging vascular activity dynamically at a microscopic scale in a vascular network of an organ of a human or animal, and the organ including one more isolated ultrasound contrast agents injected by an ultrasound agent injection device, the method including:

• (a) performing by a computing module a temporal series of Ultrasound Localization Microscopy, ULM, images of at least one region of the vascular network from a set of raw data acquired by an array of ultrasonic transducers, to obtain values of at least one vascular dynamics parameter in at least one area of interest in the at least one region during a recording period, the temporal series of ULM images being constructed from a temporal series of images of the region, each ULM image being constructed from a stack of images of the temporal series of images, at least some of the images of a stack of images corresponding to a (k+1)th ULM image having a time position superior to that of the images of a stack of images corresponding to a kth ULM image which is immediately preceding the (k+1)th ULM image, said recording period of the temporal series of ULM images including at least one dynamic event, due to a cause other than cardiac pulsatility, the at least one dynamic event activating a change in a local hemodynamics and/or a change in a structural conformation of the vascular network in the at least one region thereof;
• (b) computing by the computing module, based on the values of the at least one vascular dynamics parameter from the temporal series of ULM images, a measure of an evolution of the at least one vascular dynamics parameter in response to the at least one dynamic event.