A method and system for three dimensional scanning, imaging and/or therapy are provided. In accordance with one aspect, an exemplary method and system are configured to facilitate controlled scanning within one-degree of freedom. For example, an exemplary method and system can enable multiple two-dimensional image planes to be collected in a manner to provide an accurate and computationally efficient three-dimensional image reconstruction while providing the user with a user-friendly mechanism for acquiring three-dimensional images. In accordance with an exemplary embodiment, the positioning system comprises a guide assembly configured to provide pure rectilinear or rotational motion of the probe during scanning operation, and a position sensing system configured to detect the direction and position of the probe during scanning.
