Abstract: Selected artifacts, which may be based on distortions or selected attenuation features, may be reduced or removed from a reconstructed image. Various artifacts may occur due to the presence of a metal object in a field of view. The metal object may be identified and removed from a data that is used to generate a reconstruction.

Abstract: The present invention is directed to a novel tomographic reconstruction framework that explicitly models the covariance of the measurements in the forward model using a mean measurement model and a noise model. This more accurate model can result in improved image quality, increased spatial resolution, and enhanced detectability—in particular, for imaging scenarios where there are features on the order of the correlation length in the projection data. Applications where these methods might have particular benefit include high resolution CBCT applications as in CBCT mammography (where very fine calcifications are difficult to resolve due to detector blur and correlation), musculoskeletal imaging (where fine bone details are important to the imaging task), or in temporal bone imaging where the fine detail structures of the inner ear are also difficult to resolve with standard imaging techniques.

Abstract: The present invention is directed to a novel tomographic reconstruction framework that explicitly models the covariance of the measurements in the forward model using a mean measurement model and a noise model. This more accurate model can result in improved image quality, increased spatial resolution, and enhanced detectability—in particular, for imaging scenarios where there are features on the order of the correlation length in the projection data. Applications where these methods might have particular benefit include high resolution CBCT applications as in CBCT mammography (where very fine calcifications are difficult to resolve due to detector blur and correlation), musculoskeletal imaging (where fine bone details are important to the imaging task), or in temporal bone imaging where the fine detail structures of the inner ear are also difficult to resolve with standard imaging techniques.

Abstract: An example CT scanner assembly includes a gantry having a first end and a second end rotatable about a first axis, an x-ray detector adjacent the first end, and an x-ray source adjacent the second end. The x-ray source directs an x-ray beam toward a portion of the x-ray detector. The x-ray source translates along a second axis aligned with the first axis when the gantry rotates.

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 automatically determines a volume of change based upon anatomical changes in a patient. During surgery, the CT scanner takes a sufficient number of two-dimensional initial images using a full field of view. The CT scanner compares the initial images to pre-operative data. Based upon the comparison, the CT scanner automatically determines the volume of change plus some margin to define a volume of interest. The CT scanner then collimates an x-ray source to perform an intra-operative updated CT scan of the volume of interest. The CT scanner updates the pre-operative data with the data from the intra-operative updated CT scan of the volume of interest to form a fully updated three-dimensional CT image. The initial images and the pre-operative data can be taken at a lower resolution than the intra-operative updated CT scan of the volume of interest to reduce the 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.

Abstract: A CT scanner system provides projection-like images of a patient volume. After a CT scan is obtained and a three-dimensional model of the patient is created, any synthetic view can be generated by choosing any array of projection lines, e.g. between a point and a surface (a flat plane, curved plane, spherical, etc) or between two surfaces (parallel or not) and summing across the projection lines. The synthetic projections can mimic certain traditional views, such as a ceph scan, Water's view, Caldwell's projection, etc or can provide a new view that is impossible or impractical with traditional x-ray equipment, such as a perfect parallel projection, or a projection that does not pass all the way through the patient.