An MRI-guided interventional system includes a frame with a cooperating targeting cannula. The frame is configured to be secured to the body of a patient, and is configured to translate and rotate such that the targeting cannula can be positioned to a desired intrabody trajectory. The frame may include one or more MRI-visible fiducial markers that allow frame location/orientation to be determined within an MRI image. A plurality of user-activatable actuators are configured to translate and rotate the frame relative to the body of a patient so as to position the targeting cannula to a desired intrabody trajectory. The targeting cannula includes an axially-extending guide bore therethrough that is configured to guide placement of an interventional device in vivo. Various instrumentation and equipment, such as stimulation leads, ablation catheters, injection catheters, etc., can be inserted through the targeting cannula to execute diagnostic and/or surgical procedures.