1. A method comprising: accessing image data representing tissue; identifying one or more features of the tissue indicated by the image data; selecting a model for the tissue based on the one or more identified features; segmenting the image data; and identifying, using the model, one or more anatomical landmarks of the tissue indicated by the segmented image data; wherein the model is selected from a plurality of reference models, each reference model corresponding to a different one of a plurality of different patient populations; wherein each of the reference models relates to the corresponding patient population, and includes a set of attributes relating to the corresponding patient population; and wherein selecting the model for the tissue based on the one or more identified features includes selecting one of the reference models based on a comparison of the one or more identified features with the set of attributes of each of the plurality of reference models.