A method implemented by a volume of activation visualization machine, the method comprising: displaying, by a processor of the machine and via a display device of the machine, a model of a portion of a patient anatomy, including a plurality of anatomical structures; displaying, by the processor and via the display device, a VOA associated by the processor with a set of stimulation parameter settings, the display of the VOA overlaying the display of the model; and graphically identifying interactions between the displayed VOA and a first subset of the anatomical structures associated with one or more stimulation benefits and a second subset of the anatomical structures associated with one or more stimulation side effects, the graphical identifications differing depending on whether the interaction is with the first subset or the second subset; characterized in that: the method further comprises determining a location, with respect to the model of the portion of the brain anatomy, of a stimulation leadwire that includes directional electrodes implanted in the portion of the patient anatomy and used for a stimulation estimated to provide the displayed VOA when programmed with the set of stimulation parameter settings; and displaying, overlaid on the model of the portion of the patient anatomy, a model of the stimulation leadwire; wherein the stimulation leadwire includes a plurality of markers (2400, 2402) offset from each other with respect to a center longitudinal axis of the stimulation leadwire by a number of degrees, the offsets being adapted for indicating the direction in which the directional electrodes point when the leadwire is implanted in a patient and the markers are viewed under an imaging modality; and the determining of the location includes rotationally locating the leadwire by: outputting a set of images of a portion of the leadwire including the markers, the set of images including a respective image for each rotation of the leadwire by a certain number of degrees; and receiving user input selecting one of the output images of the portion of the leadwire including the markers. displaying, by a processor of the machine and via a display device of the machine, a model of a portion of a patient anatomy, including a plurality of anatomical structures; displaying, by the processor and via the display device, a VOA associated by the processor with a set of stimulation parameter settings, the display of the VOA overlaying the display of the model; and graphically identifying interactions between the displayed VOA and a first subset of the anatomical structures associated with one or more stimulation benefits and a second subset of the anatomical structures associated with one or more stimulation side effects, the graphical identifications differing depending on whether the interaction is with the first subset or the second subset; the method further comprises determining a location, with respect to the model of the portion of the brain anatomy, of a stimulation leadwire that includes directional electrodes implanted in the portion of the patient anatomy and used for a stimulation estimated to provide the displayed VOA when programmed with the set of stimulation parameter settings; and displaying, overlaid on the model of the portion of the patient anatomy, a model of the stimulation leadwire; wherein the stimulation leadwire includes a plurality of markers (2400, 2402) offset from each other with respect to a center longitudinal axis of the stimulation leadwire by a number of degrees, the offsets being adapted for indicating the direction in which the directional electrodes point when the leadwire is implanted in a patient and the markers are viewed under an imaging modality; and the determining of the location includes rotationally locating the leadwire by: outputting a set of images of a portion of the leadwire including the markers, the set of images including a respective image for each rotation of the leadwire by a certain number of degrees; and receiving user input selecting one of the output images of the portion of the leadwire including the markers. wherein the stimulation leadwire includes a plurality of markers (2400, 2402) offset from each other with respect to a center longitudinal axis of the stimulation leadwire by a number of degrees, the offsets being adapted for indicating the direction in which the directional electrodes point when the leadwire is implanted in a patient and the markers are viewed under an imaging modality; and the determining of the location includes rotationally locating the leadwire by: outputting a set of images of a portion of the leadwire including the markers, the set of images including a respective image for each rotation of the leadwire by a certain number of degrees; and receiving user input selecting one of the output images of the portion of the leadwire including the markers. outputting a set of images of a portion of the leadwire including the markers, the set of images including a respective image for each rotation of the leadwire by a certain number of degrees; and receiving user input selecting one of the output images of the portion of the leadwire including the markers.