An MRI-guided interventional system includes a trajectory guide frame for guiding an interventional device with respect to a patient in an MRI-guided procedure and including a base, a platform, a targeting cannula, and a stabilizer mechanism. The platform is mounted on the base and includes a support table and a moving plate that is translatable relative to the support table and the base along a translational axis. The targeting cannula is mounted on the moving plate for movement therewith and includes an elongate guide bore defining a trajectory axis. The stabilizer mechanism is operable to selectively control movement between the support table and the moving plate to stabilize a position of the targeting cannula with respect to the base. The frame is operable to translate the moving plate along the translational axis relative to the base to position the trajectory axis. The translational axis is transverse to the trajectory axis.