Abstract: A surgical navigation system includes a CT scanner that takes a plurality of x-ray images of a patient. A patient tracker including locators is attached to the patient, and a registration appendage is removably secured to the patient tracker in a known position and orientation. The registration appendage includes radio-opaque markers arranged in a predetermined geometric pattern. The registration appendage is viewable in a CT scan in situations where the locators of the patient tracker are outside of a field of view of the CT scanner.

Abstract: A surgeon selects a volume of interest by placing an untracked “marker” in a patient near an area where an update is desired. During surgery, when an updated CT scan is requested, the CT scanner performs a scan of the patient using a full field of view to take a series of two-dimensional initial images of the patient from a plurality of angularly spaced positions about the patient. The position of the untracked marker is determined by the CT scanner in or more of the initial images. The volume of interest is defined as the position of the untracked marker, plus some margin. The CT scanner then collimates the x-ray source to scan only the volume of interest. The CT scanner then completes the update scan of the volume of interest and updates a previous CT scan(s) to create a fully updated CT image, reducing x-ray exposure of the patient.

Abstract: A CT scanner includes a pair of shields to protect an operator from x-rays from the CT scanner. The CT scanner has a gantry that provides structural support and housing for the components including an x-ray source and a detector arranged on the gantry to face one another. Lead shields are located on opposing sides of the x-ray source and extend between the x-ray source and the detector. The CT scanner further includes a computer located on an opposing side of the gantry from the x-ray source and the detector. The lead shields rotate with the gantry and prevent the x-ray from reaching the operator while the CT scanner is in operation.

Abstract: A CT scanner includes a plurality of cone-beam x-ray sources offset along a CT axis. A detector is positioned opposite the x-ray sources. The x-ray sources and detector are rotatable about the CT axis. The x-ray sources direct x-rays through the patient that are received by the detector at a plurality of rotational positions, thereby generating projections from the plurality of x-ray sources that are used to construct the three-dimensional CT image of the patient.

Abstract: A CT scanning system provides the ability to scan a patient's lower extremities while the patent is upright, i.e. either standing on the foot, or at least putting some load on the foot, or with the ankle at a given angle. The CT scanning system provides a generally horizontal upper support surface on which the patient's foot is supported. A gantry supporting an x-ray source and x-ray detector are rotated about a z-axis through the support surface. With the CT scanning system, the patient's lower extremities can be scanned while under load.