Abstract: A method for associating EKG waveform data with computed tomography image data using a data synchronization scheme including generating the EKG waveform data using an electrocardiogram device, operating a computed tomography imaging system so as to create the computed tomography image data, communicating an exposure marker-in signal to the electrocardiogram device such that the exposure marker-in signal is associated with the EKG waveform data and processing the computed tomography image data, the EKG waveform data and the exposure marker-in signal, so as to correlate the EKG waveform data with the computed tomography image data. Also claimed is a medium encoded with a machine-readable computer program code for associating EKG waveform data with image data generated by an imaging system using a data synchronization scheme, the medium including instructions for causing controller to implement the aforementioned method.

Abstract: A method and apparatus for use with a gated CT imaging system for correcting for Rpeak errors in a heart beat signal, the method including identifying heart rate corresponding to each specific heart beating cycle and comparing the heart rate for each specific cycle to moving averages to determine when a likely Rpeak error has occurred and, when a likely error has occurred, modifying the heart beat signal to generate a more accurate signal and thereby render more accurate gated images.

Abstract: A method and system for associating ECG waveform data with medical imaging data using ECG gating for dose reduction and image improvement by generating the ECG waveform data using an electrocardiogram device. The ECG data is first validated and then QRS complexes are detected using a detection function. An underlying cardiac rhythm based on the detected QRS complexes is analyzed and an even number N of substantially normally shaped consecutive QRS complexes are selected. An RR interval between consecutive QRS complexes is computed to yield N−1 intervals. Duration of a representative cardiac cycle by averaging at least a plurality of the N−1 intervals is determined. Once a representative cardiac cycle is determined, a method to control power and improve image quality with the presence of patient's having arrhythmias is disclosed.

Abstract: A method and apparatus for use with a gated CT imaging system for correcting for Rpeak errors in a heart beat signal, the method including identifying heart rate corresponding to each specific heart beating cycle and comparing the heart rate for each specific cycle to moving averages to determine when a likely Rpeak error has occurred and, when a likely error has occurred, modifying the heart beat signal to generate a more accurate signal and thereby render more accurate gated images.

Abstract: A method of evaluating a substance scoring system comprises acquiring data from a phantom using an imaging system, moving at least a portion of the phantom during the acquiring step, and generating an actual substance score for the phantom based on the data acquired using the imaging system. The phantom simulates a human organ such as a human heart. The phantom is provided with a motion profile that simulates a motion profile of the human organ.

Abstract: A method is described for evaluating substance scoring, the scoring based on imaging system-generated images of an object having regions of interest due to possible presence of the substance, the method including the steps of simulating the regions of interest using a phantom having a plurality of volumes, each volume having dimensions simulating dimensions of a region of interest, each volume having a density representative of a substance density; generating images of the phantom; scoring the substance based on the phantom images; and comparing results of the substance scoring to expected phantom-image results. The above-described phantom and method allow a scoring system user to verify substance scoring accuracy and to compare scores resulting from different imaging systems, scanning methods and reconstruction algorithms.

Abstract: A method for associating EKG waveform data with computed tomography image data using a data synchronization scheme including generating the EKG waveform data using an electrocardiogram device, operating a computed tomography imaging system so as to create the computed tomography image data, communicating an exposure marker-in signal to the electrocardiogram device such that the exposure marker-in signal is associated with the EKG waveform data and processing the computed tomography image data, the EKG waveform data and the exposure marker-in signal, so as to correlate the EKG waveform data with the computed tomography image data. Also claimed is a medium encoded with a machine-readable computer program code for associating EKG waveform data with image data generated by an imaging system using a data synchronization scheme, the medium including instructions for causing controller to implement the aforementioned method.

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: A method and system for performing coronary artery calcification scoring using an imaging system including obtaining image data; examining the image data so as to identify a plurality of discrete pixel elements, wherein each of the pixel elements includes a pixel value; dividing the pixel elements into a scorable region so as to create a plurality of scorable pixel elements; processing the scorable pixel elements so as to identify a center scorable pixel element and determine a median pixel value; and replacing the pixel value for the center scorable pixel element with the median pixel value. Also claimed is a medium encoded with a machine-readable computer program code for performing coronary artery calcification scoring, the medium including instructions for causing controller to implement the aforementioned method.

Abstract: A method of evaluating a substance scoring system comprises acquiring data from a phantom using an imaging system, moving at least a portion of the phantom during the acquiring step, and generating an actual substance score for the phantom based on the data acquired using the imaging system. The phantom simulates a human organ such as a human heart. The phantom is provided with a motion profile that simulates a motion profile of the human organ.

Abstract: An apparatus and method for simulating cardiac motion for use with an imaging system are provided. The apparatus includes an expandable balloon-like member having a number of protrusions fluidly connected thereto. Fluid is circulated between the pump and a fluid reservoir by a pump which is controlled by a programmable controller. Imaging data is acquired during circulation of the fluid between the reservoir and the phantom and subsequently analyzed to determine the effectacy and efficiency of the imaging protocol.

Abstract: One aspect of the present invention is a method that includes helically scanning an object at a selected helical pitch to acquire projection data of the object. The acquired projection data includes conjugate samples from single rows of the detector array of the CT imaging system and interrow samples. Projections in a plane of reconstruction (POR) are estimated based upon a selection of the projection data from the group consisting of the conjugate samples from at least one of the single rows, the interrow samples, and combinations thereof, the selection dependent upon the selected helical pitch. The estimated projections are filtered and backprojected to reconstruct at least one image of the object.

Abstract: One aspect of the present invention is a method that includes helically scanning an object at a selected helical pitch to acquire projection data of the object. The acquired projection data includes conjugate samples from single rows of the detector array of the CT imaging system and interrow samples. Projections in a plane of reconstruction (POR) are estimated based upon a selection of the projection data from the group consisting of the conjugate samples from at least one of the single rows, the interrow samples, and combinations thereof, the selection dependent upon the selected helical pitch. The estimated projections are filtered and backprojected to reconstruct at least one image of the object.

Abstract: A method is described for controlling x-ray exposure during gated cardiac scanning, including the steps of detecting a first cardiac signal; starting scanning after a pre-selected wait time after detecting the first cardiac signal; and stopping the scanning after a first to occur of passage of a pre-selected data collection time and detection of a second cardiac signal.

Abstract: A method for generating an image of an object using a computed tomography (CT) imaging system, which includes at least one x-ray detector array and at least one rotating x-ray source projecting an x-ray beam, includes the steps of identifying a physiological cycle of the object (the cycle comprising a plurality of phases); selecting at least one phase of the object; collecting at least one segment of projection data for each selected phase of the object during each rotation of each x-ray source; generating a projection data set by combining the projection data segments; generating a cross-sectional image of the entire object from the projection data set; and communicating the image or data associated with the image to a remote facility. The remote facility provides remote services over a network.

Abstract: The present invention, in one form is an imaging system for generating images of an entire object. In one embodiment, a physiological cycle unit is used to determine the cycle of the moving object. By altering the rotational speed of an x-ray source as a function of the object cycle, segments of projection data are collected for each selected phase of the object during each rotation. After completing a plurality of rotations, the segments of projection data are combined and a cross-sectional image of the selected phase of the object is generated. As a result, minimizing motion artifacts.

Abstract: The present invention, in one form, is an imaging system for generating images of an entire object. In one embodiment, a physiological cycle unit is used to determine the cycle of the moving object. By altering the rotational speed of an x-ray source as a function of the object cycle, segments of projection data are collected for each selected phase of the object during each rotation. After completing a plurality of rotations, the segments of projection data are combined and a cross-sectional image of the selected phase of the object is generated. As a result, minimizing motion artifacts.

Abstract: Methods and corresponding apparatus for imaging a portion of a patient's body with a computed tomographic imaging system configured to scan the patient's body at a cyclically varying view angle, in which the imaging system includes a radiation source and detector array providing a fan angle width of image data. In one embodiment, the method includes axially scanning the portion of the patient's body, gating the radiation source on over less than a 360 °view angle cycle of the axial scan, acquiring image data of the portion of the patient's body during at least a portion of the time the radiation source is gated on, and assembling the acquired image data into an image of the portion of the patient's body.

Abstract: The present invention, in one form, is an imaging system which includes a verification system for verifying the proper connection of an interconnection cable. In accordance with one embodiment of the verification system, a verification circuit verifies operation of the interconnection cable by altering the patterns supplied from an EKG subsystem. More specifically, the conduction of interconnection cable is verified prior to, during and after scanning the patient by transmitting patterns received from the EKG subsystem through the verification circuit back to the EKG subsystem. If the patterns match the expected patterns, a verification signal is generated indicating proper cable connection.

Abstract: An autozeroing apparatus is disclosed for correcting the offset error in a computerized axial tomography (CAT) scanner data acquisition subsystem (DAS). The DAS includes a floating point amplifier for applying discrete amplification factors, or gain range segments, to an analog input before conversion to digital in an A/D converter. A digital autozero circuit is connected to the output of the A/D converter and adds a digital offset value to each A/D converter sample during data acquisition to correct for the net offset errors throughout the DAS. Separate storage latches are included for storing offset values corresponding to each gain range segment, and the offset value used for each sample correction corresponds to the gain range segment used for that sample. During an autozero reference interval, a reference voltage is applied to the DAS and the offset values are updated so as to force the corrected A/D converter output to agree with the reference voltage.