Abstract: A method for generating an adaptively interpolated projection of an object with an imaging system includes generating a first projection using a first interpolation kernel, generating a second projection using a second interpolation kernel, different from the first interpolation kernel, and taking a difference between the first projection and the second projection to generate a differential signal.

Abstract: One aspect of the present invention is a method for reconstructing computed tomographic (CT) images. The method includes generating a plurality of projection data, calculating a plurality of base weights using the projection data for each series of images to be reconstructed, storing the base weights in an external memory, and applying a z-smoothing module to the base weights to determine a plurality of final weights. The view weighting process then includes applying the final weights to the projection data for each image.

Abstract: A method for transmitting a scan mode to an imaging system includes loading a least significant nibble into a first latch register and loading a most significant nibble into a second latch register such that a byte of information is received at a decoder.

Abstract: A photographing cycle including a weak ultrasonic monitor image photographing step of photographing monitor images by using a weak enough ultrasonic wave not to let the contrast agent disappear, a strong ultrasonic B mode image photographing step of photographing a B mode image by using a strong enough ultrasonic wave to make the contrast agent disappear, and a weak ultrasonic CFM image photographing step for photographing CFM images by using a weak enough ultrasonic wave not to let the contrast agent disappear is iterated. The latest image resulting from the addition of the CFM image is displayed superposed over the B mode image.

Abstract: A method of correcting a resonance frequency variation and an MRI apparatus both capable of handling all frequency drifts including a frequency drift whose time change is slow, a frequency drift in a slice direction and a frequency drift whose time change is fast. An amount of a resonance frequency variation is measured, the frequency variation is corrected when an amount of the resonance frequency variation is smaller than a threshold value, and the amount of the resonance frequency variation is not stored. On the other hand, when the amount of the resonance frequency variation is not smaller than the threshold value, the amount of the resonance frequency variation is stored and correction operation is made based thereon later.

Abstract: A CT imaging system and method are provided in which groups of adjacent detector elements of a detector array are ganged in an x-direction; and an object is scanned using the ganged groups of adjacent detector elements to acquire projection data. In one embodiment, to reduce degradation of images resulting from the ganged detector elements, an image of the object is reconstructed utilizing the acquired projection data and an adjusted iso-channel of the multislice detector array different from an iso-channel defined for scans performed without utilizing ganged groups of detector elements.

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: In one aspect, there is provided a method for reducing aliasing artifacts in a computed tomography system. The method includes scanning an object with a computed tomography system to acquire a projection data set of measured views; synthesizing additional views of the projection data set utilizing view interpolation; and filtering and backprojecting the projection data set utilizing a weighting function dependent upon parameters Rƒ and Rt, where radius Rƒ around an isocenter of the CT imaging system is selected in accordance with a low artifact criterion and Rt is a parameter defining a transition region outside of radius Rƒ around the isocenter of the CT imaging system.

Abstract: A detector module includes a photosensor array having a first width, and a flexible cable operationally coupled to the photosensor array, wherein the cable has a width greater then the first width.

Abstract: A method for reducing imaging artifacts in at least one image representative of an object with a scanning imaging system is provided. The imaging system has a multislice detector array and a radiation source configured to emit a radiation beam through the object and towards the multislice detector array. The multislice detector array has a plurality of detector elements arranged in a plurality of detector rows. The method includes scanning the object with the scanning imaging system to acquire a plurality of projection data acquired from a plurality of detector rows including two end rows and a plurality of interior detector rows. The method also includes defining a first plane of reconstruction (POR) for a particular detector row, and defining a second plane of reconstruction (POR) for the particular detector row.

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: A method for facilitating a reduction in reconstructed image noise in a computed tomography imaging system. The method includes generating projection data, characterizing a noise distribution of the projection data, performing an adaptive noise reduction operation on the projection data using the noise distribution characterization, and filtering the projection data.

Abstract: Degradation in reconstructed medical images is reduced by a method for calibrating a primary decay correction for a radiation detector having a decay curve that can be characterized by a plurality of components having different time constants. The method includes steps of: fitting the decay curve to a sum of a plurality of weighted exponentials having a first set of time constants; applying a correction to a measured response of the detector using a sum of the plurality of weighted exponentials having the first set of time constants to obtain a corrected response; selecting at least one additional exponential time constant dependent upon the corrected response; and fitting the decay curve to a sum of a second plurality of weighted exponentials including the first plurality of time constants and the at least one additional exponential time constant.

Abstract: There is therefore provided, in one aspect, a method for imaging an object utilizing a computed tomographic (CT) imaging system having a rotating gantry, a multislice detector array on the rotating gantry and using at least n>1 rows of detector channels, and a radiation source on the rotating gantry configured to project a beam of radiation towards the multislice detector array through an object to be imaged. The method includes helically scanning the object with the CT imaging system at a pitch p>n to acquire projection data from the n rows of detector channels; applying a combined helical weight and conjugate weight to at least a portion of the acquired projection data to produce virtual projection data compensating for incomplete helical row data of the acquired projection data; and reconstructing an image of the object utilizing the acquired projection data and the virtual projection data.

Abstract: A method for reconstructing a computed tomographic (CT) image of an object is provided. The method includes initializing a CT imaging system in a step-and-shoot mode, scanning an object to generate a plurality of adjacent axial scans, wherein the distance between the adjacent axial scans is approximately equal to a projected detector height at the detector iso-center, and reconstructing an image of the object using the adjacent axial scans.

Abstract: Methods and apparatus for reducing motion-induced artifacts in CT imaging is described. The imaging system scans a patient's heart to obtain a plurality of projection views, a differential projection is determined from the projection views, a weighting function is applied to the differential projection to minimize motion artifacts, and an inconsistency index is determined from the differential projection, and the inconsistency index is used to locate an image reconstruction location. This method directly measures the mechanics of the heart, rather than an electrical signal and utilizes projection data to select the best locations to minimize image artifact.

Abstract: One embodiment of the present invention is a detector for detecting x-rays of an imaging system. The detector has a plurality of photodetectors; and a plurality of scintillator elements optically coupled to the plurality of photodetectors. The scintillator elements have sides separated from adjacent scintillator elements by gaps; and a cast reflector mixture in the gaps between the sides of the scintillator elements. The cast reflector mixture include a first powdered material having a higher Z and a higher density than titanium dioxide, and a refractivity index sufficient to effectively scatter and reflect light within the cast reflector mixture.

Abstract: A method and apparatus for correcting ghost artifacts that are related to orthogonal perturbation magnetic fields is disclosed. The technique includes acquiring MR data and an MR reference scan, each in the presence of orthogonal perturbation magnetic fields. However, the region of interest for the MR reference scan is limited to a relatively narrow band within the imaging subject. Preferably, the narrow band is selected in the vicinity of the magnet iso-center and parallel to the readout direction. Alternatively, the narrow band can also be selected in the limited region where the orthogonal perturbation fields are either minimal or constant along the phase encoding direction, and parallel to the readout direction. The selection of the relatively narrow band is accomplished by either spatially saturating surrounding regions, or using a two-dimensional spatially selective RF pulse.

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: In one aspect, the present invention relates to tube-spit detection and correction. In an exemplary embodiment, and once a sample of projection data has been collected, the projection data is preprocessed in accordance with known preprocessing algorithms including applying a detector primary speed correction to the projection data. Such primary speed correction removes contamination of previous signal sample from the current sample. After primary speed correction, tube-spit detection is performed on the sample. Such detection can be performed using many different methods. Generally, the objective is to determine whether the x-ray source experienced a drop in power. If a tube-spit event is not detected, then processing proceeds with further preprocessing and image reconstruction. If a tube-spit event is detected, then a tube spit correction is performed. Generally, the objective of tube-spit correction is to remove image artifacts due to the occurrence of a tube-spit event.