A device in the form of an elongated articulating arm having a base for mounting it on or at the MRI apparatus. The free end of the arm is arranged to releasably mount any type of device, e.g., a clamp, a bracket, a biopsy needle guide, etc. The arm includes a plurality of interconnected segments each of which is arranged to pivot about a respective axis perpendicular to the longitudinal axis of the arm, but restricted from twisting about the longitudinal axis. A flexible elongated adjustable tensioning member in the form of plural sections of a cord extend through respective ones of plural flexible sheaths within the arm between the base and the distal end portion to enable the arm to be moved or bent into a desired shape when tension is released and then held in that shape when tension is applied.