Abstract: A mechanism for rapidly detecting and localizing external markers placed on a patient in projection images. Embodiments of the invention allow the markers to be detected even in the presence of dense surrounding anatomy and extensive patient motion. Once the positions of the marker points on the projection images are extracted, the marker points can be used to perform marker-based patient motion detection. Embodiments of the invention can also be used outside of motion correction, such as for scanner calibration, automatic cephalometric measurements, and quality control assessment.

Abstract: A system and method for automatic detection of x-rays at an x-ray sensor. A source emits x-ray radiation towards an x-ray sensor, and the x-ray sensor automatically detects the x-ray radiation. The x-ray sensor automatically detects x-ray radiation by evaluating a time series and determining that a voltage threshold is crossed a certain amount of time earlier than the average time it takes the voltage threshold to be crossed from dark current and other noise.

Abstract: A method and a system for generating a panoramic x-ray image by obtaining volumetric x-ray image data having a first plurality of slices, segmenting the x-ray image data into a first portion above a vertical threshold and a second portion below the vertical threshold, and separating the second portion into a second plurality of slices. Further, the method and the system include generating a plurality of curves for each slice in the second plurality of slices, generating a master arch for the second plurality of slices, and generating a panoramic image based on the master arch.

Abstract: For dental and facial imaging, a source of x-rays (14) or other penetrating radiation and a detector (20) are mounted opposite one another on a rotatable gantry (28), so that the head of the patient can be positioned between the source (14) and the detector (20), with the axis of rotation (36) of the gantry passing through the patient's head. The detector is longer in one direction than in the perpendicular direction, generally rectangular, and is rotatable between a position in which the long axis is transverse to the axis of rotation of the gantry and a position in which the long axis is generally parallel to the axis of rotation of the gantry. The length of the detector along the long axis is sufficient for fully detailed computed CT when the long axis is transverse, and for full-face CT when the long axis is parallel.

Abstract: A method and system of determining a radial distance (R), an angular position (?), and an axial position (Z) of a marker identified in a sequence of projection images. A marker three-dimensional localization module (executable by the electronic processing unit) obtains a sequence of images based on image data generated by a scanner. Each image in the sequence of images represents an angle of rotation by the scanner and includes a marker point position. The behavior of first values and second values of the marker point positions are analyzed through the sequence of images to determine the radial distance of the marker, the angular position of the marker, and the axial position of the marker allowing for rapidly detecting and localizing external markers placed on a patient in projection images.

Abstract: A system and method for automatic detection of x-rays at an x-ray sensor. A source emits x-ray radiation towards an x-ray sensor, and the x-ray sensor automatically detects the x-ray radiation. The x-ray sensor automatically detects x-ray radiation by evaluating a time series and determining that a voltage threshold is crossed a certain amount of time earlier than the average time it takes the voltage threshold to be crossed from dark current and other noise.

Abstract: A method of displaying tomographic information. The method comprises defining a compact region within an imaged target and generating an image showing a part of the target encircling the compact region, wherein the compact region represents a bore to be drilled and the generated image shows a perspective view of the wall of the bore from an open end of the bore.

Abstract: A method of and apparatus for enhancing an array of values, which may be tomographic data, are disclosed. The values are divided into categories. Values in at least one first category are smoothed by replacing an original individual value with a new individual value determined from a plurality of neighboring values. The values in at least one second category are retained relatively unsmoothed.

Abstract: A method and apparatus for locating an elongated object in a three dimensional data array are disclosed. A slice of data generally lengthways of the elongated object is selected. Points on the object in the selected slice are identified. Data including the points are transposed parallel to the slice and transversely to the elongated object to align the points in a direction parallel to the slice and transverse to the elongated object. A current slice is selected that is rotated around the length direction of the object relative to the previously selected slice. The identifying and transposing are repeated to align points on the object in a direction parallel to the current slice and transverse to the elongated object.

Abstract: In a method and apparatus for locating in a three dimensional data array an arcuate object having an axial extent, slices of data generally transverse to the axial extent of the object are selected. Rays generally radially of the arcuate object are selected within the slices. Crossing points where the rays cross the boundaries of the arcuate object are located. The position of the arcuate object is determined from the positions of the located points.

Abstract: An apparatus for generating a panoramic image of part of a target, the apparatus including a source of penetrating radiation and a detector aligned with the source of penetrating radiation. The detector and source of penetrating radiation are rotate-able together with respect to the target. The detector has an array of radiation sensors arranged in rows and columns and is configured to output contents of each radiation sensor in the array of radiation sensors. The apparatus also includes a computer connected to the detector and configured to generate a panoramic image by combining data from sensors in the same row in different columns in different readout intervals, corresponding to different positions of the detector as it rotates with respect to the target. The combined outputs are selected to represent rays of radiation passing through a point on a defined curve.

Abstract: In a method and apparatus for generating a view of a jaw, a tomographic dataset of a volume including at least part of the jaw is obtained. Inner and outer surfaces of the jaw are identified in the tomographic dataset. Data for a region with boundaries related to the identified inner and outer surfaces are selected. A panoramic view is generated from the selected data and is displayed.

Abstract: A method and apparatus for generating a panoramic image of part of a target, comprises providing a scanner having a source of penetrating radiation facing a detector having an array of sensors for the penetrating radiation. The target is positioned between the source of penetrating radiation and the detector, and scanned with relative rotation of the scanner and the target. Radiation received at a plurality of the sensors spaced apart in the circumferential direction of the relative rotation is separately recorded. A panoramic image is generated by combining for each pixel of the panoramic image outputs from different sensors at different times during the relative rotation, the combined outputs being selected to represent rays of radiation passing through a point on a defined curve. The generated panoramic image and a graphical representation of the defined curve are displayed. Instructions are received from a user to alter the defined curve.

Abstract: A method of and apparatus for displaying tomographic information are disclosed. A compact region within an imaged target is defined. An image is generated showing part of the target encircling the compact region.

Abstract: In a method and apparatus for locating in a three dimensional data array an arcuate object having an axial extent, slices of data generally transverse to the axial extent of the object are selected. Rays generally radially of the arcuate object are selected within the slices. Crossing points where the rays cross the boundaries of the arcuate object are located. The position of the arcuate object is determined from the positions of the located points.

Abstract: A method and apparatus for generating a panoramic image of part of a target, comprises providing a scanner having a source of penetrating radiation facing a detector having an array of sensors for the penetrating radiation. The target is positioned between the source of penetrating radiation and the detector, and scanned with relative rotation of the scanner and the target. Radiation received at a plurality of the sensors spaced apart in the circumferential direction of the relative rotation is separately recorded. A panoramic image is generated by combining for each pixel of the panoramic image outputs from different sensors at different times during the relative rotation, the combined outputs being selected to represent rays of radiation passing through a point on a defined curve. The generated panoramic image and a graphical representation of the defined curve are displayed. Instructions are received from a user to alter the defined curve.

Abstract: A method and apparatus for locating an elongated object in a three dimensional data array are disclosed. A slice of data generally lengthways of the elongated object is selected. Points on the object in the selected slice are identified. Data including the points are transposed parallel to the slice and transversely to the elongated object to align the points in a direction parallel to the slice and transverse to the elongated object. A current slice is selected that is rotated around the length direction of the object relative to the previously selected slice. The identifying and transposing are repeated to align points on the object in a direction parallel to the current slice and transverse to the elongated object.

Abstract: In a method and apparatus for generating a view of a jaw, a tomographic dataset of a volume including at least part of the jaw is obtained. Inner and outer surfaces of the jaw are identified in the tomographic dataset. Data for a region with boundaries related to the identified inner and outer surfaces are selected. A panoramic view is generated from the selected data and is displayed.