Abstract: A system for registering images using retrospective gating, the system comprising: an imaging system; an object disposed to be communicated with the imaging system, wherein the imaging system generates image data responsive to said object; and a processing device. The processing device executes a method comprising: determining a target area of interest; obtaining scout image data responsive to the target area; and processing the target area so as to create a sub-target area of interest. The method also includes computing a desired image acquisition time; operating said imaging system to create image data responsive to each sub-target area; combining the image data for each of the sub-target areas to create a set of image data; processing the image data to determine a phase of the image data; and synchronizing the image data.

Abstract: The present invention is directed to a method and apparatus of cardiac CT imaging. The present invention utilizes ECG signals as well as mechanical motion signals of a cardiac region of a subject to correlate CT data acquired of the subject with the phases of the subject's cardiac region. The present invention contemplates measuring mechanical gatings of the heart by measuring changes in pressure, sound, or blood flow acceleration within the cardiac region. The mechanical gatings are then used with ECG data to correlate acquired imaging data with phases of the cardiac region for subsequent image reconstruction.

Abstract: A method and apparatus for imaging a heart with a scanning computed tomography (CT) imaging system. A cardiac cycle of a patient is measured. The patient's heart is then scanned with the scanning CT imaging system at an angular rate asynchronous to the measured cardiac cycle to obtain image data. An image of the patient's heart is then assembled from chronologically discontinuous segments of the image data. The image is representative of a selected portion of the cardiac cycle.

Abstract: One embodiment of the present invention is a method for reconstructing cardiac images using a computed tomographic (CT) imaging system. The method includes steps of: selecting a helical scanning pitch for scanning a patient; scanning the patient, including the patient's heart, with a computed tomographic imaging system having a plurality of detector rows and a rotating gantry to acquire projection data from the plurality of detector rows; selecting a phase of the cardiac cycle for imaging; combining portions of the acquired projection data from a plurality of detector rows, the combined portions corresponding to the selected cardiac phase; and reconstructing images, including images of the patient's heart, from the combined, interpolated projection data.

Abstract: A method for acquiring and analyzing cardiac data of a patient includes acquiring a first volume of cardiac data from a medical scanner, processing the first volume of cardiac data for image reconstruction and visualization, acquiring a subsequent plurality of volumes of cardiac data from the medical scanner, processing the subsequent plurality of volumes of cardiac data for image reconstruction and visualization, and reconstructing and visualizing the first and subsequent plurality of image sets from the acquired first and the subsequent plurality of volumes of cardiac data, respectively. The method for acquiring and analyzing cardiac data of a patient includes processing the cardiac images for detection and diagnosis of heart diseases.

Abstract: The present invention is directed to a method and apparatus of cardiac CT imaging. The present invention utilizes ECG signals as well as mechanical motion signals of a cardiac region of a subject to correlate CT data acquired of the subject with the phases of the subject's cardiac region. The present invention contemplates measuring mechanical gatings of the heart by measuring changes in pressure, sound, or blood flow acceleration within the cardiac region. The mechanical gatings are then used with ECG data to correlate acquired imaging data with phases of the cardiac region for subsequent image reconstruction.

Abstract: A system and method of medical imaging using a variable speed patient positioning table are provided. The patient positioning table is configured to operate at a plurality of table speeds during acquisition of data from a selected region, such as the thorax region baying predefined cardiac and non-cardiac regions. In a non-cardiac region, the table is controlled to move at one speed and when the cardiac region is detected, the table is controlled to move at another speed, preferably faster than in the cardiac region to speed data acquisition and eliminate motion artifacts.

Abstract: In one aspect, the present invention is a method for scanning an object with a multi-slice CT imaging system having multiple detector rows each having an isocenter. The method includes steps of helically scanning an object with the multi-slice CT imaging system to obtain data segments including peripheral data segments, combining data from a first peripheral data segment with an opposite, second peripheral segment to form a data set for reconstruction of an image slice; and reconstructing the combined data into image slices.

Abstract: The invention includes a technique for efficient multi-slice fast spin echo image acquisition with black blood contrast in cardiac imaging. The technique includes applying a non-selective inversion pulse, followed by a re-inversion pulse that is slice-selective over a region encompassing a plurality of slice selections. Execution of a series of RF excitation pulses with fast spin echo readout is timed such that signal from blood is near a null point before acquiring data for each spatial slice. For greater contrast consistency, the flip angles for the excitation pulses occurring before the null point can be reduced, and those occurring after the null point can be increased.

Abstract: One aspect of the present invention is a method for multisector computed tomographic (CT) imaging of a cyclically moving object, including steps of: helically scanning a cyclically moving object with a CT imaging system having multiple detector rows and a rotating gantry, at a gantry rotation speed selected either to lead or to lag a cycle of the cyclically moving object; retrospectively gating the projection data of the object with a gating signal related to the motion of the cyclically moving object so that a geometric phase difference is created between a cycle of the rotating gantry and the motion of the cyclically moving object; and reconstructing an image of the cyclically moving object using gated sector data from image data representing a plurality of consecutive cycles of the cyclically moving object.

Abstract: One aspect of the present invention is a method for multisector computed tomographic (CT) imaging of a cyclically moving object, including steps of: helically scanning a cyclically moving object with a CT imaging system having multiple detector rows and a rotating gantry, at a gantry rotation speed selected either to lead or to lag a cycle of the cyclically moving object; retrospectively gating the projection data of the object with a gating signal related to the motion of the cyclically moving object so that a geometric phase difference is created between a cycle of the rotating gantry and the motion of the cyclically moving object; and reconstructing an image of the cyclically moving object using gated sector data from image data representing a plurality of consecutive cycles of the cyclically moving object.

Abstract: One embodiment of the present invention is a method for reconstructing cardiac images using a computed tomographic (CT) imaging system. The method includes steps of: selecting a helical scanning pitch for scanning a patient; scanning the patient, including the patient's heart, with a computed tomographic imaging system having a plurality of detector rows and a rotating gantry to acquire projection data from the plurality of detector rows; selecting a phase of the cardiac cycle for imaging; combining portions of the acquired projection data from a plurality of detector rows, the combined portions corresponding to the selected cardiac phase; and reconstructing images, including images of the patient's heart, from the combined, interpolated projection data.

Abstract: Methods and apparatus for calibration simplification in a computed tomography (CT) system are described. In one embodiment, the CT system utilizes calibration values from a first scan type, or mode of operation, to determine calibration values for at least a second scan type. As a result, the time required to perform calibration of the CT system is reduced.

Abstract: A method and apparatus for use with a multi-row CT fan beam system for collecting data in a high speed mode and for using data corresponding to half-scans in order to generate images within one or more image planes wherein, for each beam angle corresponding to an image plane data is generated by interpolating and/or extrapolating between simultaneously collected data wherein simultaneously collected data includes data corresponding to a single source location with respect to the image plane.

Abstract: In one aspect, the present invention is a method for imaging an object utilizing a multi-slice CT imaging system having an x-ray source, a detector array, and a data acquisition system coupled to the detector array, the data acquisition system having a number of data acquisition input channels less than a total number of detector cells in the detector array. The method includes steps of: positioning the object between the x-ray source and the detector array; projecting an x-ray beam towards the object; and selectively reconfiguring a coupling of selected detector cells to the data acquisition input channels to increase a number of image slices received by the data acquisition system.

Abstract: Methods and apparatus for reconstructing an image of an object utilizing an imaging system, in which a limited width beam of radiation is emitted towards the object, the limited width beam of radiation having a fan beam angle extent selected to encompass a perimeter of a region of interest (ROI) within the object and to encompass less than a perimeter of the object itself; a set of truncated projection data of the object, including projection data of the ROI, is obtained by detecting the radiation from the limited width beam of radiation passing through the object; low frequency components of the set of truncated projection data are estimated; and an image of the ROI within the object is reconstructed utilizing the set of truncated projection data and the estimated low frequency components. Information from a limited set of complete projection data can be used to estimate the low frequency components of the set of truncated projection data, but such information is not required.

Abstract: A spectral correction algorithm for correcting dense object-induced spectral artifacts is described. In one embodiment, a calibration object, representative of typical head scanning conditions is scanned and the data reconstructed to provide an image. A water or water-equivalent cylinder of about the same diameter also is scanned and reconstructed, on the same display field of view (DFOV). These two images are designated respectively by BWEQ and WEQ. The ratio of images BWEQ and WEQ is then evaluated, and a region of interest extracted by multiplying the ratio by a function II(r), to obtain a calibration pattern CP. The calibration pattern is then averaged in azimuth to obtain a calibration vector. This calibration vector is fitted with low--order polynomial, and then divided by the fitting polynomial, to take out from the vector the low frequency components that, for instance, would be introduced on an "ideal" scanner. By subtracting 1.

Abstract: An isolation method for a semiconductor device, and comprises the steps of: sequentially forming a first silicon nitride film, an oxide film, and a second silicon nitride film on a substrate and forming an opening to define an isolation region between devices; forming a spacer at the edges of the opening and implanting impurities in the substrate; removing the exposed part of the first silicon nitride film, and then removing the spacer; growing a field oxide film, and sequentially removing the second silicon nitride film, the oxide film, and the first silicon nitride film. In a second embodiment, the first silicon nitride film and part of the substrate are removed, and then the spacer is removed during the process of removing the exposed part of the first silicon nitride film and the spacer. Accordingly, the depth to which the field oxide film is buried is controlled by the etching depth of the substrate, thereby increasing the effective isolation distance.