摘要:
The present invention, in one form, is a system which predicts contrast agent uptake in an organ of interest. In accordance with one embodiment, and after the contrast agent has been administered to a patient, a prep scan is performed to determine a base contrast agent uptake measurement. A predictive algorithm is then applied to the base measurement to predict a subsequent contrast agent uptake measurement. The predicted subsequent measurement is then compared to a scanning parameter. Particularly, if the predicted subsequent measurement satisfies the scanning parameter, then an image scan is initiated. If the predicted subsequent measurement does not satisfy the scanning parameter, however, then an additional prep scan is performed to determine a new base contrast agent uptake measurement. The predictive algorithm is then applied to the new base measurement to predict a subsequent contrast agent uptake measurement. The prep scans and predictions are repeated until the predicted subsequent contrast agent uptake measurement satisfies the scanning parameter.
摘要:
The present invention, in one form, is a method for improving grey-white matter differentiation between regions of an image to be reconstructed from data obtained by a CT scan. More particularly, in accordance with one form of the present invention, a re-mapping function is utilized to generate CT numbers. In accordance with such function, CT numbers that are outside the grey-white matter region are not "stretched". The CT numbers within such region are "stretched" with the larger "stretch" centered on the grey-white matter region and tapering off at the boundary. Using such a function, grey-white matter differentiation is improved without adversely affecting quality and accuracy.
摘要:
The present invention, in one form, is a system for obtaining data measurement signals for producing a tomographic image of an object in a multislice scan. More specifically, detector cells in at least one channel of a detector array are electrically coupled, or ganged, so that the ganged channel provides one data measurement signal to be transmitted through the gantry slip ring. The signal distribution in the z-direction for the ganged channel is then determined using signals obtained by adjacent non-ganged detector cells.
摘要:
The present invention, in one form, is a method for improving image quality in Computed Tomography systems by using a partial volume artifact estimation algorithm. In accordance with one embodiment of the algorithm, an object of interest is scanned to generate image data. The image data is segmented into low attenuation data and high attenuation data. A gradient image is generated for two adjacent slices of the image data. The gradient image is then forward projected and squared. The squared gradient image is an estimation of partial volume artifacts in the image data, and therefore is removed from the image data.
摘要:
Precise alignment of the focal spot position on an x-ray CT system is achieved using a deflection coil that produces a magnetic field which acts on the electron beam path in the x-ray tube. A variable current power supply drives the deflection coil and is controlled by input signals to align the focal spot at a static reference position, to correct for focal spot drift between scans, and to wobble the focal spot position during a scan or between scans.
摘要:
Streaking artifacts in a computed tomography x-ray image are reduced by adaptively filtering each set of projection data. The adaptive filter produces an error vector (.theta.) by low-pass filtering the projection data (P) and subtracting the error vector (.theta.) from the projection data (P) prior to image reconstruction. A window function generator controls the low-pass filter as a function of x-ray detector readings.
摘要:
A method for reconstructing an image of an object that includes a plurality of image elements. The method includes accessing image data associated with a plurality of image elements, and reconstructing an image of the object by optimizing an objective function, where the objective function is optimized by iteratively solving a nested sequence of approximate optimization problems. The algorithm is composed of nested iterative loops, in which an inner loop iteratively optimizes an objective function approximating the outer loop objective function, and an outer loop that utilizes the solution of the inner loop to optimize the original objective function.
摘要:
A method for reconstructing an image of an object includes acquiring a set of measured projection data, reconstructing the measured projection data using a first algorithm to generate a first reconstructed image dataset, reconstructing the measured projection data using a second algorithm to generate a second reconstructed image dataset, the second algorithm being utilized to improve the temporal resolution of the second reconstructed image dataset, and generating a final image dataset using both the first and second image datasets.
摘要:
A method is provided. The method includes acquiring a first dataset at a first energy spectrum and a second dataset at a second energy spectrum. The method also includes extracting a metal artifact correction signal using the first dataset and the second dataset or using a first reconstructed image and a second reconstructed image generated respectively from the first and the second datasets. The method further includes performing metal artifact correction on the first reconstructed image using the metal artifact correction signal to generate a first corrected image.
摘要:
A method includes fitting a motion map from a first imaging modality with a first FOV to a second imaging modality different from the first with a second FOV sized differently than the first FOV.