An ultrasound imaging system, comprising: an intraluminal imaging device comprising a flexible elongate member configured to be positioned within a body lumen of a patient and an ultrasound transducer array coupled to the flexible elongate member, the ultrasound transducer array configured to obtain first signal data and second signal data representative of the body lumen, wherein the first signal data and the second signal data are associated with different imaging modes of the ultrasound transducer array; and a processor (106, 140) in communication with the intraluminal imaging device and configured to: generate motion data of a fluid flow within the body lumen based on the first signal data, wherein the motion data includes flow intensities representing the fluid flow within the body lumen; generate structural data of the body lumen based on the second signal data, wherein the structural data includes B-mode intensities representing the body lumen; determine whether to assign a first flow intensity of the flow intensities in the motion data or a first B-mode intensity of the B-mode intensities in the structural data to a combined motion data and structural data based on a first threshold; assign the first B-mode intensity to the combined motion data and structural data when the first B-mode intensity exceeds the first threshold; output, to a display in communication with the processor, an intraluminal ultrasound image representing the combined motion data and structural data. an intraluminal imaging device comprising a flexible elongate member configured to be positioned within a body lumen of a patient and an ultrasound transducer array coupled to the flexible elongate member, the ultrasound transducer array configured to obtain first signal data and second signal data representative of the body lumen, wherein the first signal data and the second signal data are associated with different imaging modes of the ultrasound transducer array; and a processor (106, 140) in communication with the intraluminal imaging device and configured to: generate motion data of a fluid flow within the body lumen based on the first signal data, wherein the motion data includes flow intensities representing the fluid flow within the body lumen; generate structural data of the body lumen based on the second signal data, wherein the structural data includes B-mode intensities representing the body lumen; determine whether to assign a first flow intensity of the flow intensities in the motion data or a first B-mode intensity of the B-mode intensities in the structural data to a combined motion data and structural data based on a first threshold; assign the first B-mode intensity to the combined motion data and structural data when the first B-mode intensity exceeds the first threshold; output, to a display in communication with the processor, an intraluminal ultrasound image representing the combined motion data and structural data. generate motion data of a fluid flow within the body lumen based on the first signal data, wherein the motion data includes flow intensities representing the fluid flow within the body lumen; generate structural data of the body lumen based on the second signal data, wherein the structural data includes B-mode intensities representing the body lumen; determine whether to assign a first flow intensity of the flow intensities in the motion data or a first B-mode intensity of the B-mode intensities in the structural data to a combined motion data and structural data based on a first threshold; assign the first B-mode intensity to the combined motion data and structural data when the first B-mode intensity exceeds the first threshold; output, to a display in communication with the processor, an intraluminal ultrasound image representing the combined motion data and structural data.