摘要:
In an image reconstruction method for imaging a periodically moving object with a computed tomography apparatus employing a multi-line detector unit, suitable selection of the rotational speed of the carrier of the computed tomography apparatus and employment of a three-dimensional back-projection algorithm, allow qualitatively high-great images of the object to be produced in every motion phase.
摘要:
In a spiral scan cone beam computed tomography method and apparatus, the output data are divided into sub-segments being shorter than the length required for the reconstruction of a CT image. Segment images having inclined image plane relative to the system axis are reconstructed for the sub-segments. A signal reproducing the time curve of the periodic motion is acquired during the scanning. A z-position on the system axis and a time position with respect to the periodic motion are allocated to the segment images. Segment images belonging to a desired range of z-positions and a desired range of time positions are selected such that the corresponding sub-segments have an overall length adequate for the reconstruction of a CT image. The selected segment images are at least indirectly combined into a resulting CT image with respect to a target image plane.
摘要:
The invention relates to a method for performing computer tomography, and to a computed tomography (CT) apparatus, in which a) for scanning an object by a cone-shaped beam exiting from a focal point and by a matrix-like detector array for detecting the beam, the focal point is moved in relation to the object on a spiral path, whose center axis corresponds to a system axis, and the detector array provides output data corresponding to the received radiation; and b) for imaging an object region that executes a periodic motion, a signal that reproduces the course over time of the periodic motion is obtained during the scanning; c) from output data furnished during the motion of the focal point on a spiral segment, images with an inclined image plane are reconstructed, the image planes being inclined relative to the system axis both about a first axis, which perpendicularly intersects the system axis, by an angle of inclination &ggr; and about a second axis, which perpendicularly intersects both the first axis and the system axis, by a tilt angle &dgr;; and spiral segments that immediately succeed one another overlap one another by an overlap angle that is greater than or equal to zero; and the spiral segments are selected, taking into account the signal that reproduces the course over time of the periodic motion, such that they correspond to a phase of the periodic motion that is to be imaged.
摘要:
A method is for producing CT images of at least one second organ cyclically excited to move by a first organ moving on its own, or examination area with rest phases and activity phases of a patient. The second organ or the examination area is scanned, preferably spirally. A three-dimensional image of the absorption coefficient is determined with the aid of a multiplicity of cutting planes on the basis of the data obtained by scanning in the rest phase of the second organ or examination area, and the movement information required to determine the rest phase is collected from the first organ.
摘要:
In a method to support the diagnosis and/or therapy of a pathological change of a blood vessel of a patient, in particular in the context of coronary heart disease at a first point in time of a pixel-based or voxel-based first image is acquired with the blood vessel of interest by an imaging method, a determination is made from the first image of a quantity of existing non-calcified plaque and a quantity of existing calcium-rich plaque, a determination of a first indicator value is made from the quantities of the different plaque types that represents a measurement of the quantity and the composition of plaque present in the blood vessel at the first point in time, a comparison of the first indicator value is made with at least one limit value stored in a storage of a data processing device, and dependent on the comparison, a presentation is made on an output unit associated with the electronic data processing device of either a proposal for a measure to be undertaken on the patient, or a proposal for no measure.
摘要:
A method is for producing CT images of at least one second organ cyclically excited to move by a first organ moving on its own, or examination area with rest phases and activity phases of a patient. The second organ or the examination area is scanned, preferably spirally. A three-dimensional image of the absorption coefficient is determined with the aid of a multiplicity of cutting planes on the basis of the data obtained by scanning in the rest phase of the second organ or examination area, and the movement information required to determine the rest phase is collected from the first organ.
摘要:
A contrast agent for medical imaging has a component in the form of a chemical compound of gadolinium that is effective for x-ray computed tomography, that has at least one additive that prevents use of the contrast agent in magnetic resonance tomography.
摘要:
In a method for examining a body region executing a periodic motion in an examination subject with a diagnostic apparatus having a radiation source for generating radiation penetrating the examination subject and a detector system for the radiation emanating from the radiation source, the intensity of the radiation emanating from the radiation source is modulated between a reference value and a reduced value compared to the reference value, substantially synchronously with the movement, so that the reference value is present during a phase of the periodic motion to be imaged with the diagnostic apparatus, and substantially only the data that were output by the detector system during the presence of the reference value of the radiation are utilized for the determination of the image.
摘要:
In a method and CT apparatus for producing CT images of a body region periodically moving with resting or motion phases, data corresponding to a number of projections serving the purpose of imaging are analyzed to determine whether each projection was acquired during a resting or motion phase, and only those data that were acquired during a resting phase are employed for image reconstruction.
摘要:
In a method and device for, generating computed tomography images of a periodically moving organ of an organism, the organ having regions with rest phases and movement phases and the rest phases of different regions ensuing at different points in time, an x-ray source is moved around the body of the organism to be examined to generate projections serving for the image generation during at least one rotation of the x-ray source around the subject to be examined and during a duration that is at least equal to a period of the motion. The projection data are analyzed as to whether the data were acquired during a rest phase or movement phase of a respective region of interest of the organ, and an image of the organ is reconstructed using only data acquired during a rest phase of a respective region of interest of the organ.