Fluid flow detection for ultrasound imaging devices, systems, and methods
Ultrasound image devices, systems, and methods are provided. An ultrasound imaging system, comprising an intraluminal imaging device including an ultrasound transducer array configured to obtain first signal data and second signal data representative of a body lumen, the first signal data and the second signal data associating with different imaging modes of the ultrasound transducer array; and a processor in communication with the intraluminal imaging device and configured to generate motion data of a flow within the body lumen based on the first signal data; generate structural data of the body lumen based on the second signal data; combine the motion data and the structural data based on a first threshold; and output, to a display in communication with the processor, an intraluminal ultrasound image representing the combined motion data and structural data.
1 . An ultrasound imaging system, comprising:
an intravascular imaging catheter comprising:
a flexible elongate member configured to be positioned within a blood vessel of a patient heart; and
a circumferential ultrasound transducer array coupled to the flexible elongate member, wherein the ultrasound transducer array is configured to obtain first signal data and second signal data associated with different imaging modes; and
a processor configured for communication with the intravascular imaging catheter, and wherein the processor is configured to:
generate, based on the first signal data, motion data representative of first motion and second motion, wherein the first motion is blood flow motion and the second motion is tissue motion, wherein the motion data comprises a plurality of vectors spatially distributed around the circumferential ultrasound transducer array, wherein each vector of the plurality of vectors comprises a plurality of samples representing a plurality of imaging depths away from the ultrasound transducer array;
distinguish between the first motion and the second motion, wherein, to perform the distinguishing, the processor is configured to:
determine, based on the first signal data, a respective average signal level for each imaging depth of the plurality of imaging depths; and
apply the respective average signal level to each sample at a corresponding imaging depth in the plurality of vectors;
generate structural data based on the second signal data, wherein the structural data represents the blood vessel;
combine the motion data and the structural data to determine motion pixels and structure pixels forming an intravascular image, wherein the distinguishing and the determination of the motion pixels and structure pixels are distinct from one another; and
output the intravascular image to a display in communication with the processor.
2 . The system of claim 1 ,
wherein the processor is configured to apply a noise threshold to the respective average signal level,
wherein the noise threshold is associated with a noise level of the first signal data.
3 . The system of claim 1 , wherein the processor is configured to normalize the motion data by applying a scaling function to the motion data based on the corresponding imaging depth.
4 . The system of claim 1 ,
wherein the motion data includes flow intensities,
wherein the structural data includes B-mode intensities,
wherein the processor is configured to combine the motion data and the structural data by:
determining 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 the combined motion data and structural data based on an intensity threshold.
5 . The system of claim 4 , wherein the processor is configured to combine the motion data and the structural data by:
assigning the first B-mode intensity to the combined motion data and structural data when the first B-mode intensity exceeds the intensity threshold.
6 . The system of claim 4 , wherein the processor is configured to combine the motion data and the structural data by:
assigning the first flow intensity to the combined motion data and structural data when the first B-mode intensity is equal to or below the intensity threshold.
7 . The system of claim 4 , wherein the intensity threshold varies as a function of the first flow intensity.
8 . The system of claim 4 ,
wherein the motion data includes flow intensities,
wherein the structural data includes B-mode intensities,
wherein the processor is configured to combine the motion data and the structural data by:
selecting a value from a lookup table based on a first flow intensity of the flow intensities in the motion data, a first B-mode intensity of the B-mode intensities in the structural data, and a co-registration between the motion data and the structural data, the lookup table including B-mode intensities and flow intensities associated with the intensity threshold; and
assigning the selected value to the combined motion data and structural data.
9 . The system of claim 8 , wherein the flow intensities in the lookup table includes at least 256 flow intensity levels.
10 . The system of claim 4 , wherein the processor is configured to:
compute the intensity threshold comprising a value that varies according to values of intensities that are present during intravascular imaging.
11 . The system of claim 1 ,
wherein the circumferential ultrasound transducer array comprises a plurality of acoustic elements arranged around a longitudinal axis of the flexible elongate member,
wherein the first signal data is acquired based on a first imaging mode configured with an aperture including a first quantity of the plurality of acoustic elements, and
wherein the second signal data is acquired based on a second imaging mode configured with an aperture including a second quantity of the plurality of acoustic elements different from the first quantity.
12 . The system of claim 1 , further comprising:
the display configured to display the intravascular image by:
displaying a first region of the intravascular image associated with the motion data in color; and
displaying a second region of the intravascular image associated with the structural data in gray-scale.
13 . The system of claim 1 ,
wherein the motion data comprise at least one of flow intensities, color intensities, or chroma intensities, and
wherein the structural data comprise at least one of B-mode intensities, gray-scale intensities, or brightness intensities.
14 . A method of ultrasound imaging, comprising:
receiving first signal data and second signal data representative of a blood vessel of a patient heart during intravascular imaging, wherein the first signal data and the second signal data are acquired from a circumferential ultrasound transducer array of an intravascular imaging catheter and coupled to a flexible elongate member positioned within the blood vessel, wherein the first signal data and the second signal data are associated with different imaging modes;
generating, based on the first signal data, motion data representative of first motion and second motion, wherein the first motion is blood flow motion and the second motion is tissue motion, wherein the motion data comprises a plurality of vectors spatially distributed around the circumferential ultrasound transducer array, wherein each vector of the plurality of vectors comprises a plurality of samples representing a plurality of imaging depths away from the ultrasound transducer array;
distinguish between the first motion and the second motion, wherein the distinguishing comprises:
determining, based on the first signal data, a respective average signal level for each imaging depth of the plurality of imaging depths; and
applying the respective average signal level to each sample at a corresponding imaging depth in the plurality of vectors;
generating structural data based on the second signal data, wherein the structural data represents the blood vessel;
combining the motion data and the structural data to determine motion pixels and structure pixels forming an intravascular image, wherein the distinguishing and the determination of the motion pixels and structure pixels are distinct from one another; and
outputting, to a display, the intravascular image.