摘要:
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.
摘要:
In one aspect, the present invention is a method for automatically positioning an object, such as a patient, on a movable table using pre-scan scout data. High and low edges and a center of the object are determined as a function of object position in a z-axis direction. At least one threshold is determined from which to determine whether to move the table. The table is automatically repositioned based on comparison of the thresholds to respective distances of the high edge, low edge and center of the object from isocenter. The above described method allows automatic and dynamic adjustment of the table height to a position that prevents over-range while allowing use of higher gains to reduce image noise.
摘要:
A method for obtaining data includes scanning an organ with an imaging system emitting X-rays and modulating the emitted X-rays with an organ specific bowtie addition.
摘要:
A system and method of diagnostic imaging with reduced x-ray exposure to the scan subject during scanning includes acquiring a set of cardiac signals or other motion (cardiac mechanical motion or respiratory motion) related signals and determining and imaging profile therefrom. Pursuant to the imaging profile, voltage applied to an x-ray source is modulated to provide an energizing voltage during primary data acquisition stages and a reduced voltage during secondary or non-data acquisition stages. Voltage modulation repeats until sufficient data for image reconstruction has been acquired.
摘要:
Methods and systems for generating computed tomographic (CT) images from image data acquired during different biological cycles are provided. A computer is programmed to receive a plurality of scan data acquired during a gated acquisition window of each of a plurality of biological cycles, blend the scan data acquired during a first of the plurality of biological cycles with the scan data acquired during a second of the plurality of biological cycles, and construct a final image from the blended data.
摘要:
The present invention is directed to a method and system of controlling rotation of a gantry to rotate at a rotational speed such that a desired relationship between center projection angles of neighboring partial scans is maintained.
摘要:
The present invention is directed to a method and system of blending data acquired from neighboring partial-scans. Data is acquired from an imaging volume in a series of fractional or partial-scans. Each partial-scan samples a fraction of the imaging volume. During reconstruction, data from the partial-scans are combined to compensate for the unsampled portion of the imaging volume that is experienced in any partial-scan alone.
摘要:
A method for combining images acquired using helical half-scan imaging comprises identifying an image plane within an overlap region comprising data from first and second view streams representative of first and second cycles of acquired image data. The image plane comprises the same anatomical structure. First and second weighting functions are calculated for first and second images based on first and second tube positions of an x-ray tube. The first and second images correspond to the image plane and are from the first and second view streams, respectively. The first and second tube positions also correspond to the image plane. A weighted image is then formed based on the first and second weighting functions and the first and second images.
摘要:
Method and apparatus for locally enhancing image data represented as pixels having CT numbers is provided. The image data includes bony structures, and the method comprises segmenting pixels within the image data into areas based on the pixel's CT number. A first area represents a combination of soft tissue and lower density bones and a second area represents higher density bones. A subset of pixels is identified within the first area representative of the lower density bones. An enhancement is applied to the subset of pixels within the first area and to the second area to create an enhanced dataset, and a locally enhanced image is generated based on the image data and the enhanced dataset.
摘要:
A method for reconstructing an image of an object includes scanning an object using a computed tomographic (CT) imaging apparatus to acquire projections of the object. A set of thresholds are determined utilizing the projections, and selected smoothing kernels are associated with the thresholds. The method further includes utilizing the smoothing kernels and the projections to produce smoothed projections in accordance with the thresholds and filtering and backprojecting the smoothed projections to generate an image of the object.