A system is provided for use during a medical procedure. The system has at least one sensing device holder configured to hold a radiation sensing device, a ring guide, and a rod which connects the holder to the ring guide. The ring guide includes a ring having a central opening and first and second connecting portions extending outwardly therefrom. The ring defines horizontal and vertical axes which pass through an axial centerline of the ring guide. Each connecting portion has a channel which accepts the rod therethrough and which is parallel to the axial centerline. The channel of the first connecting portion intersects the horizontal axis, and is offset from the vertical axis. The channel of the second connecting portion is offset from the horizontal and vertical axes. The rod can be attached to either of the connecting portions.
