A system comprising: - a computer memory storing a computer program, - a camera tracking system and - a dynamic reference array which comprises: - a scaffold; - a plurality of markers coupled to the scaffold, wherein the plurality of markers includes tracking markers trackable by a camera tracking system and fiducial markers viewable on a medical image, wherein the medical image is a CT scan; and - an attachment member coupled to the scaffold with a swivel feature, wherein the attachment member is configured to secure the scaffold to the patient while allowing movement of the scaffold with respect to the attachment member, - wherein, during swiveling, the tracking markers and the fiducial markers of said plurality of markers are moved between a first position and a second position relative to an additional tracking marker coupled to the attachment member , - wherein in the first position, the attachment member positions the plurality of markers coupled to the scaffold in a first position near the patient suitable for obtaining the medical image from the fiducial markers and in the second position, the attachment member positions the plurality of markers coupled to the scaffold away from the patient suitable for tracking the tracking markers with the camera tracking system , wherein the computer program, when executed by a computer, causes the computer to compare the relative positioning of the tracking markers coupled to the scaffold and the additional tracking marker with a configuration that is stored in computer memory during any given tracking frame obtained by the camera tracking system so as to determine whether the plurality of markers coupled to the scaffold are in the first or in the second position relative to the additional tracking marker in order to prevent a user from inadvertently track and navigate before the plurality of markers are swiveled into the second position, wherein the plurality of markers are reflective tracking spheres with a metallic or ceramic core that is radio-opaque. - a computer memory storing a computer program, - a camera tracking system and - a dynamic reference array which comprises: - a scaffold; - a plurality of markers coupled to the scaffold, wherein the plurality of markers includes tracking markers trackable by a camera tracking system and fiducial markers viewable on a medical image, wherein the medical image is a CT scan; and - an attachment member coupled to the scaffold with a swivel feature, wherein the attachment member is configured to secure the scaffold to the patient while allowing movement of the scaffold with respect to the attachment member, - wherein, during swiveling, the tracking markers and the fiducial markers of said plurality of markers are moved between a first position and a second position relative to an additional tracking marker coupled to the attachment member , - wherein in the first position, the attachment member positions the plurality of markers coupled to the scaffold in a first position near the patient suitable for obtaining the medical image from the fiducial markers and in the second position, the attachment member positions the plurality of markers coupled to the scaffold away from the patient suitable for tracking the tracking markers with the camera tracking system , <EOS>