Abstract: A method for reducing imaging artifacts includes preprocessing a computed tomography (CT) projection data set to generate preprocessed CT projection data, filtering the preprocessed CT projection data using a mean-preserving filter (MPF) to reduce electronic noise, generating a sinogram using the filtered CT projection data, performing a minus logarithmic operation on the sinogram to generate a noise corrected image, and displaying the noise corrected image on a display. A imaging correcting module and a multi-modality imaging system are also described herein.

Abstract: Anode targets for an x-ray tube and methods for controlling x-ray tubes for x-ray systems are provided. One x-ray system includes a field-generator configured to generate a field, an electron beam generator configured to generate an electron beam directed towards a target and a voltage controller configured to control the electron beam generator to produce an electron beam at a first energy level and an electron beam at a second energy level. The x-ray system also includes a field-generator controller configured to control a field to deflect at least one of the electron beams, wherein the electron beam, at the first energy level, impinges on the target at a first contact position and the electron beam, at the second energy level, impinges on the target at a second contact position. The at the first contact position and at the second contact position is configured to filter x-rays.

Abstract: A computed tomography (CT) detector array includes a central region substantially symmetric about a central axis thereof and includes a first plurality of x-ray detector cells configured to acquire CT data from a first number of detector rows during a scan, wherein the central axis is in a channel direction of the CT detector array and transverse to a slice direction of the CT detector array. A first wing is coupled to a first side of the central region, and a second wing is coupled to a second side of the central region opposite the first side. The first and second wings include respective second and third pluralities of x-ray detector cells and are each configured to acquire CT data from a number of detector rows that is less than the first number of detector rows. The CT detector array is asymmetric about the central axis of the central region.

Abstract: A computed tomography (CT) detector array includes a central region substantially symmetric about a central axis thereof and includes a first plurality of x-ray detector cells configured to acquire CT data from a first number of detector rows during a scan, wherein the central axis is in a channel direction of the CT detector array and transverse to a slice direction of the CT detector array. A first wing is coupled to a first side of the central region, and a second wing is coupled to a second side of the central region opposite the first side. The first and second wings include respective second and third pluralities of x-ray detector cells and are each configured to acquire CT data from a number of detector rows that is less than the first number of detector rows. The CT detector array is asymmetric about the central axis of the central region.

Abstract: A system, method, and apparatus includes a computed tomography (CT) detector array having a central region with a plurality of central region detecting cells configured to acquire CT data of a first number of slices during a scan, a first wing along a first side of the central region, and a second wing along a second side of the central region opposite the first side. The first wing includes a plurality of first wing detecting cells configured to acquire CT data of a second number of slices during the scan. The second wing includes a plurality of second wing detecting cells configured to acquire CT data of a third number of slices during the scan. The second and third number of slices are less than the first number of slices. The first wing detecting cells are of a different type than the central region detecting cells.

Abstract: A computed tomography (CT) system that includes a rotational gantry and a stationary structure communicatively coupled to the rotational gantry is provided. The rotational gantry includes an X-ray source configured to emit an X-ray beam through a subject, an X-ray detector comprising one or more detector elements that receive incoming X-rays and to convert the incoming X-rays to image signals, and a data acquisition unit that processes the image signals to generate processed image data. The stationary structure is coupled to the rotational gantry via one or more slip rings that transfer the processed image data from the rotational gantry to stationary memory integral with the stationary structure via a bidirectional serial data exchange protocol.

Abstract: An imaging system includes a rotatable gantry having an opening therein to receive a subject to be scanned and configured to rotate about a central axis in a rotation direction. The imaging system also includes a first x-ray source coupled to the rotatable gantry at a first position, wherein the first position is offset from the central axis of the rotatable gantry by a first distance. Further, the imaging system includes a second x-ray source coupled to the rotatable gantry at a second position, wherein the second position is offset from the central axis of the rotatable gantry by a second distance, wherein the second position is offset from the first position in a direction coincident with the rotation direction, and wherein the second position is offset from the first position in a direction parallel to the central axis.

Abstract: A CT system includes a rotatable gantry having an opening for receiving a subject to be scanned, a rotatable gantry having an opening for receiving a subject to be scanned, an x-ray source configured to project x-rays having multiple energies toward the subject, and a generator configured to energize the x-ray source to a first voltage and configured to energize the x-ray source to a second voltage, the first voltage distinct from the second voltage. The system further includes a controller configured to cause the generator to energize the x-ray source to the first voltage for a first duration, acquire imaging data for at least one view during at least the first duration, after the first duration, cause the generator to energize the x-ray source to the second voltage for a second duration, and acquire imaging data for two or more views during at least the second duration.

Abstract: A method for calibrating and reconstructing material density images in a dual-spectral computed tomography (CT) system 100 is disclosed. An X-ray source in the CT system 100 emits a first X-ray spectrum and a second X-ray spectrum towards an object. The method includes computing calibration coefficients by using projection data from the object for the two X-ray spectra and by linearizing at least two basis materials such as bone and water simultaneously. Further, basis materials decomposition coefficients for the at least two basis materials are computed by linearizing the basis materials individually. Correction values for the projection data and for the basis materials are then computed by using the basis materials decomposition coefficients and the calibration coefficients. The computed correction values are used in reconstructing material density images for the basis materials.

Abstract: A method for performing BIS correction includes scanning an object with a computed tomography (CT) system to obtain data, reconstructing an image using the obtained data, and using the image to perform BIS correction.

Abstract: Methods and systems for scanning a patient by using a medical imaging device are provided. The methods include determining a defective cell in a row n of a detector of the medical imaging device, determining a mode of operation of the medical imaging device, estimating the output of the defective cell using the determined mode of operation and at least one of a conjugate sample of the defective cell, an adjusted conjugate sample of the defective cell, and an estimate of the output of the defective cell using an output of a corresponding cell in an adjacent row and reconstructing an image of the patient using the estimated value of the defective cell.

Abstract: A method for calibrating and reconstructing material density images in a dual-spectral computed tomography (CT) system 100 is disclosed. An X-ray source in the CT system 100 emits a first X-ray spectrum and a second X-ray spectrum towards an object. The method includes computing calibration coefficients by using projection data from the object for the two X-ray spectra and by linearizing at least two basis materials such as bone and water simultaneously. Further, basis materials decomposition coefficients for the at least two basis materials are computed by linearizing the basis materials individually. Correction values for the projection data and for the basis materials are then computed by using the basis materials decomposition coefficients and the calibration coefficients. The computed correction values are used in reconstructing material density images for the basis materials.

Abstract: A CT system includes a rotatable gantry having an opening for receiving a subject to be scanned, a rotatable gantry having an opening for receiving a subject to be scanned, an x-ray source configured to project x-rays having multiple energies toward the subject, and a generator configured to energize the x-ray source to a first voltage and configured to energize the x-ray source to a second voltage, the first voltage distinct from the second voltage. The system further includes a controller configured to cause the generator to energize the x-ray source to the first voltage for a first duration, acquire imaging data for at least one view during at least the first duration, after the first duration, cause the generator to energize the x-ray source to the second voltage for a second duration, and acquire imaging data for two or more views during at least the second duration.

Abstract: A method for normalizing a calibration of a computed tomographic (CT) imaging apparatus having a plurality of detector rows includes utilizing a prestored, predetermined inversion matrix and CT numbers obtained from images of a phantom to determine normalized calibration vectors for each row of a plurality of detector rows, and storing the determined normalized calibration vectors for each row of the plurality of detector rows in a memory for use in subsequent image reconstructions.

Abstract: A method for performing BIS correction includes scanning an object with a computed tomography (CT) system to obtain data, reconstructing an image using the obtained data, and using the image to perform BIS correction.

Abstract: A CT system is constructed to have diagonally oriented perimeter walls of its detector cells. A CT detector comprised of such detector cells has improved spatial coverage (spatial density) and is better equipped for operation with focal spot deflecting x-ray sources. The number of detector channels is also not increased despite the increase in spatial coverage. Moreover, the detector cells can be constructed without much variance from conventional fabrication techniques.

Abstract: A method for reconstructing an image of an object includes scanning the object with a computed tomography (CT) system to obtain data, estimating a size of the object using the obtained data, using the estimated size of the object to perform scatter correction on the obtained data, and reconstructing an image using the scatter corrected data.

Abstract: A method for reconstructing an image of an object includes scanning the object with a computed tomography (CT) system to obtain data, estimating a size of the object using the obtained data, using the estimated size of the object to perform scatter correction on the obtained data, and reconstructing an image using the scatter corrected data.

Abstract: A method for normalizing a calibration of a computed tomographic (CT) imaging apparatus having a plurality of detector rows includes utilizing a prestored, predetermined inversion matrix and CT numbers obtained from images of a phantom to determine normalized calibration vectors for each row of a plurality of detector rows, and storing the determined normalized calibration vectors for each row of the plurality of detector rows in a memory for use in subsequent image reconstructions.

Abstract: Methods and systems for scanning a patient by using a medical imaging device are provided. The methods include determining a defective cell in a row n of a detector of the medical imaging device, determining a mode of operation of the medical imaging device, estimating the output of the defective cell using the determined mode of operation and at least one of a conjugate sample of the defective cell, an adjusted conjugate sample of the defective cell, and an estimate of the output of the defective cell using an output of a corresponding cell in an adjacent row and reconstructing an image of the patient using the estimated value of the defective cell.