Improved ultrasound imaging devices and methods of using the devices are provided. An intraluminal imaging device is configured process imaging data obtained using a single imaging sequence in different processing paths to generate B-mode and flow images. For example, an ultrasound imaging system includes an ultrasound imaging device comprising an array of acoustic elements and a processor in communication with the array. The processor activates the array of acoustic elements to acquire ultrasound data using a sequence of transmit-receive pairs, generates a B-mode image using the acquired ultrasound data, forms a plurality of sub-apertures comprising a portion of the transmit-receive pairs, groups the sub-apertures into temporally-spaced ensembles, determines a flow estimate based on a comparison of at least one of sub-apertures within an ensemble, ensembles within an aperture, or different apertures, and outputs a graphical representation of the B-mode image and the flow estimate to a display.