A system and method is provided for performing a model-based segmentation of a medical image which only partially shows an anatomical structure. In accordance therewith, a model is applied to the image data of the medical image, the model-based segmentation providing an adapted model having a first model part having been adapted to the first part of the anatomical structure in the medical image of the patient, and a second model part representing the second part of the anatomical structure not having been adapted to a corresponding part of the medical image. Metadata is generated which identifies the first model part to enable the first model part to be distinguished from the second model part in a further processing of the adapted model. Advantageously, the metadata can be used to generate an output image which visually indicates to the user which part of the model has been personalized and which part of the model has not been personalized. Other advantageous uses of the metadata in the further processing of the adapted model have also been conceived.