Abstract: A computed tomography apparatus and method using line data estimated from circle data and scanogram data. An image of a subject is reconstructed using the circle data and the estimated line data. The circle data and scanogram data may be weighted in estimating the line data. The apparatus and method are useful in diminishing or eliminating streak artifacts in reconstructed images such as images including the spine.

Abstract: A method, a computational unit and a CT system are disclosed for improving the quality of CT image series. In at least one embodiment, the method includes scanning an examination object over a period of time which permits the acquisition of at least two temporally offset projection data records of an identical recording region; generating at least two temporally offset tomographic image data records, each having a multiplicity of pixels, by reconstructing the projection data records; transforming the image data records into transformation data records of at least two spatial frequency ranges; calculating temporal fitted values of the transformation data records for some of the spatial frequency ranges, and replacing the values of the transformation data records which were fitted by the calculated fitted values; performing an inverse transform of the transformation data records with the fitted values to form new image data records; and displaying the new image data records.

Abstract: At least one embodiment of the invention relates to a method for the reconstruction of image data of an examined object from measuring data, wherein the measuring data were detected by a detector within and outside of its Tam-Danielsson window during a relative spiral movement between a radiation source of a computer tomography system and the examined object. As a result of the spiral movement, the measuring data outside of the Tam-Danielsson contain interruptions. A mathematically precise first reconstruction of first image data is realized in at least one embodiment based on the measuring data by using only measuring data from the Tam-Danielsson window.

Abstract: A method is disclosed for scanning a moving examination object using a CT-System, with which data is captured during a circular movement of a transmitter/receiver pair through 360 degrees about the examination object, the data being assigned to the respective angular position. The 360 degrees are divided into n subsegments of equal size, where n is greater than 2, an even number and not divisible by 4. In at least one embodiment, the data assigned to the odd number subsegments forms a first data record and the data assigned to the even number subsegments forms a second data record. Differential information is determined between the first data record and the second data record. Motion information relating to the movement of the examination object is determined using the differential information.

Abstract: A method for centering a left atrium and pulmonary veins at an isocenter of an imaging device is provided. The method includes positioning an injection catheter at a bifurcation of a pulmonary artery; obtaining an anterior or posterior flouroscopic image of area including and/or surrounding the left atrium and pulmonary veins; and moving the imaging device, patient support, or the combination thereof, such that the injection catheter and a spine of a patient are displayed in the fluoroscopic image.

Abstract: A method of performing a computed tomographic image reconstruction is provided. The method provides for performing a short scan of an imaging object to acquire a short scan data, performing a plurality of image reconstructions based on the short scan data wherein the plurality of image reconstructions result in a corresponding plurality of image volumes wherein the image reconstructions use different view weighting functions, filtering the plurality of image volumes such that when the volumes are added together, the frequency domain data is substantially uniformly weighted. Further, the method provides for combining the plurality of image volumes together to produce a final image volume.

Abstract: An X-ray computer tomography apparatus includes an X-ray tube, an X-ray detector, a rotating mechanism, a reconstruction unit which reconstructs multislice or volume image data based on the projection data detected by the X-ray detector, a profile generating unit which generates a CT value profile in the slice direction for each pixel by using image data, a profile portion extraction unit which extracts a profile portion exceeding a predetermined threshold from each of the CT value profiles, a scattered radiation distribution estimation unit which estimates a scattered radiation distribution centered on the profile portion based on the CT value integral and width of the profile portion, and a scattered radiation correction unit which corrects the image data based on the estimated scattered radiation distribution.

Abstract: In a radiographic image detection apparatus that can perform long-size radiography on a region of a patient that is larger than the detection range of a radiographic image detector, radiography is performed so that a collimator image is included in a radiographic image in such a manner that the collimator image is present in the vicinity of a side edge of the radiographic image. Further, the inclination of each radiographic image caused by inclination of the radiographic image detector at the time of radiography is corrected based on the collimator image. Further, a synthesis image is produced by combining the plurality of radiographic images the inclination of which has been corrected.

Abstract: A computed tomography system includes a radiation sensitive detector element (100) which provides outputs (DL, DH) indicative of the radiation detected in at least first and second energies or energy ranges. Energy resolving photon counters (26) further classify the detector signals according to their respective energies. Correctors (24) correct the classified signals, and a combiner (30) combines the signals according to a combination function to generate outputs (EL, EH) indicative of radiation detected in at least first and second energies or energy ranges.

Abstract: In a method to assist in the selection of an acquisition configuration from a set of adjustable acquisition configurations for the acquisition of x-ray projections of the heart of a patient with a computed tomography apparatus to examine the heart of the patient, the which method is based on an examination type to be specified. At least two acquisition configurations for the specified examination type (which acquisition configurations can be adjusted at the computed tomography apparatus) are considered for which at least one probability density function is respectively kept ready that was determined for the respective acquisition configuration for a specific variable pertaining to a person and/or for the x-ray dose to be applied to the person.

Abstract: A method and system for detecting anatomic landmarks in medical images is disclosed. In order to detect multiple related anatomic landmarks, a plurality of landmark candidates are first detected individually using trained landmark detectors. A joint context is then generated for each combination of the landmark candidates. The best combination of landmarks in then determined based on the joint context using a trained joint context detector.

Abstract: A method for determining attenuation coefficients for an object using a movable x-ray source and a detector for recording projections is provided. The method includes defining a trajectory for the movable x-ray source, defining filtering lines for the filtering of projection data, and defining positions on the filtering lines, at which the projection derivative is to be formed using a mathematical algorithm for a back-projection. The method also includes defining sampling positions on the trajectory, traversing, by the x-ray source, the trajectory and recording a projection for each sampling position. Projection derivatives with respect to the trajectory path are calculated numerically for each of the positions directly on the filtering lines, and using a mathematical algorithm, attenuation coefficients are determined for the object from the calculated projection derivatives, for the reconstruction.

Abstract: A system and method for forming an adjusted estimate of scattered radiation in a radiographic projection of a target object, which incorporates scattered radiation from objects adjacent to the target object, such as a patient table. A piercing point equalization method is disclosed, and a refinement of analytical kernel methods which utilizes hybrid kernels is also disclosed.

Abstract: A method of obtaining a computed tomography image of an object includes determining linear terms and non-linear beam hardening terms in a pair of line integral equations for dual-energy projection data from inserting average and difference from average attenuation terms, obtaining an initial solution of the line integral equation by setting the non-linear beam hardening terms to zero, and iteratively solving the line integral equations to obtain one line integral equations for each basis material. Attenuation by the first basis material corresponds to a photoelectric attenuation process, and attenuation by the second basis material corresponds to a Compton attenuation process. The line integral equations can be inverted by an inverse Radon procedure such as filtered backprojection to give images of each basis material. The images of each basis material can then be optionally combined to give monochromatic images, density and effective atomic number images, or photoelectric and Compton processes images.

Abstract: In an X-ray CT apparatus 1 and an X-ray CT method, the thickness of an object to be inspected is computed on the basis of the number of transmitted X-rays in a specific energy range set above and below the K-absorption edge of an X-ray contrast medium serving as the object to be inspected, and a CT image is reconstructed on the basis of the computed thickness of the object to be inspected. Such X-ray CT apparatus 1 and X-ray CT method can generate an X-ray CT image stably and independently of the size of the object to be inspected and of X-ray tube voltage (X-ray energy distribution).

Abstract: Methods, systems and computer program products are provided for acquiring an image set using optical coherence tomography (OCT). A first portion of a defined volume is scanned at a low-density sampling rate to obtain a plurality of low-density frames. A second portion of the defined volume is scanned at a high-density sampling rate, higher than the low-density sampling rate, to obtain at least one high-density frame. The low-density frames and the at least one high-density frame are combined to provide a complete mixed-density image set.

Abstract: An X-ray CT apparatus is provided with an X-ray tube current modulation pattern calculation means that calculates an X-ray tube current modulation pattern based on a 3-dimensional model of an object calculated based on a scanogram image of the object, start-up shape acquisition means that acquires a start-up shape of CT values of a predetermined region of the object or CT value time differences after injecting contrast agent into the object, time contrast curve prediction means that predicts a time contrast curve indicative of a time sequential change of contrast in a diagnostic portion of the object at each slice position at a scan time based on the acquired start-up shape of the CT values or CT value time differences, object 3-dimensional model modification means that modifies a 3-dimensional model of the object based on the predicted time contrast curve, and X-ray tube electric current modulation pattern modification means that modifies the X-ray tube electric current modulation pattern based on the modifi

Abstract: Methods, systems, and related computer program products for computer-aided detection (CAD) of anatomical abnormalities in digital (or digitized) x-ray mammograms are described. The inventive techniques are based on using a foundational CAD processing algorithm that is characterized by at least one of non-shift-invariance, non-rotational-invariance, and non-inversional-invariance. According to one preferred embodiment, a first x-ray mammogram image of a breast is received, and at least one altered version thereof is generated that differs therefrom by at least one of image shift, image rotation, and image inversion. The first x-ray mammogram image and each of the at least one altered versions thereof are individually processed using the foundational CAD algorithm to generate a respective plurality of individual CAD detection sets. The plurality of CAD detection sets are then compared to generate an overall CAD detection set.

Abstract: A method of computed-tomography and a computed-tomography apparatus where a flying focal spot x-ray interpolation interlacing is used. Weighted or non-weighted interlacing of zero values is performed, or interpolation interlacing is performed. The interpolation interlacing may be implemented as part of backprojection and or may be a separate process prior to backprojection. In both cases interlacing is performed on post-logged convolved data. The interpolation interlacing may also be incorporated into different parts of the processing chain, such as before convolution.

Abstract: Fast kV-switching is a dual energy acquisition technique in computed tomography (CT) in which alternating views correspond to the low and high tube voltages. Its high temporal resolution and its suitability to a variety of source trajectories make it an attractive option for dual energy data acquisition. Its disadvantages include a one-view misregistration between the data for high and low voltages, the potentially poor spectrum separation due to the more-like a sine wave rather than the desired square wave in fast kV-switching, and the higher noise in the low voltage data because of the technical difficulty in swinging the tube current to counter the loss of x-ray production efficiency and loss of penetration at lower tube voltages.