A method for generating an ultrasound image includes receiving a sequence of intravascular ultrasound (IVUS) data obtained as an IVUS imager moves through a body lumen； identifying at least one bifurcation of the body lumen from the sequence of IVUS data； determining a bifurcation angle between two branches of the body lumen； and displaying a longitudinal view of the body lumen using the IVUS data and incorporating the bifurcation angle to angularly align portions of the longitudinal view corresponding to the two portions of the body lumen.
