Method for multi-frequency imaging and composite image display using high-bandwidth transducer outputs

A system for imaging a patient volume, comprising:

• a processor circuit in communication with an intravascular imaging device and a display, wherein the processor circuit is configured to:
• control the intravascular imaging device to obtain a first image of a blood vessel using a first frequency while the intravascular imaging device is positioned within the blood vessel;
• control the intravascular imaging device to obtain a second image of the blood vessel using a lower, second frequency while the intravascular imaging device is positioned within the blood vessel;
• form a first border line in the first image corresponding to a first depth of focus of the intravascular imaging device at the first frequency, wherein the first border line comprises a closed shape within a cross-section of the blood vessel depicted in the first image;
• identify, based on the first border line, a first depth region of the first image corresponding to the first depth of focus;
• form a second border line in the second image corresponding to a second depth of focus of the intravascular imaging device at the second frequency, wherein the second border line comprises the closed shape within the cross-section of the blood vessel depicted in the second image, wherein the first border line and the second border line are distinct from one another because of the first border line being formed in the first image and the second border line being formed in the second image;
• identify, based on the second border line, a second depth region of the second image corresponding to the second depth of focus, wherein the second depth region is farther from the intravascular imaging device than the first depth region, and wherein no portion of the second depth region overlaps with the first depth region;
• combine the first depth region of the first image and the second depth region of the second image to form a composite image of the blood vessel;
• and
• output the composite image to the display.