A system for segmentation of an anatomical structure , comprising: - an image data interface for accessing image data representing a medical image, the medical image comprising the anatomical structure to be segmented; - a model data interface for accessing model data in a database , the model data defining a plurality of models for segmenting anatomical structures, wherein each of the plurality of models is at least in part representable as a set of coordinates in a coordinate system; and - a user interaction subsystem comprising: i) a display output for displaying a view of the medical image on a display , ii) a user device input for receiving input commands from a user device operable by a user, wherein the user interaction subsystem is configured for enabling the user to indicate a set of boundary points of the anatomical structure in the view, thereby obtaining a set of coordinates in a coordinate system associated with the view; - a processor for selecting one or more of the plurality of models from the database to segment the anatomical structure in the medical image characterised by : j) determining a goodness-of-fit between the set of boundary points and each of the plurality of models based on a comparison of respective coordinates, thereby obtaining a plurality of goodness-of-fit measures, and jj) selecting the one or more of the plurality of models based on the plurality of goodness-of-fit measures, thereby obtaining one or more selected models . - an image data interface for accessing image data representing a medical image, the medical image comprising the anatomical structure to be segmented; - a model data interface for accessing model data in a database , the model data defining a plurality of models for segmenting anatomical structures, wherein each of the plurality of models is at least in part representable as a set of coordinates in a coordinate system; and - a user interaction subsystem comprising: i) a display output for displaying a view of the medical image on a display , ii) a user device input for receiving input commands from a user device operable by a user, wherein the user interaction subsystem is configured for enabling the user to indicate a set of boundary points of the anatomical structure in the view, thereby obtaining a set of coordinates in a coordinate system associated with the view; i) a display output for displaying a view of the medical image on a display , ii) a user device input for receiving input commands from a user device operable by a user, - a processor for selecting one or more of the plurality of models from the database to segment the anatomical structure in the medical image characterised by : j) determining a goodness-of-fit between the set of boundary points and each of the plurality of models based on a comparison of respective coordinates, thereby obtaining a plurality of goodness-of-fit measures, and jj) selecting the one or more of the plurality of models based on the plurality of goodness-of-fit measures, thereby obtaining one or more selected models . j) determining a goodness-of-fit between the set of boundary points and each of the plurality of models based on a comparison of respective coordinates, thereby obtaining a plurality of goodness-of-fit measures, and jj) selecting the one or more of the plurality of models based on the plurality of goodness-of-fit measures, thereby obtaining one or more selected models . <EOS>