Methods, devices, and systems for providing seamless, co-planar intravascular ultrasound (IVUS) images are provided. In some embodiments, the methods include projecting a first A-scan line from a distal frame onto a reconstruction plane that extends perpendicular to an imaging axis, projecting a second A-scan line parallel to the first A-scan line from the proximal frame on the reconstruction plane and determining a grayscale value of a point on the reconstruction plane by a weighted average of the first A-scan line and the second A-scan line.