Abstract: Methods for computed tomography data-based cycle estimation and four-dimensional reconstruction are provided. A gated reconstruction is derived from CT data acquired without gating using an added artificial trigger. The resulting images for different slices are used to determine local or slice variations over time. The local variations over time for the various slices are combined to create a respiratory cycle signal. This respiratory cycle signal is used to bin the images for different phases, allowing four-dimensional CT reconstruction.

Abstract: In an embodiment, a method includes at least moving a patient table through a measurement region of the computed tomography device, the movement of the patient having at least one phase of variable speed during the projection recording, time-solved determination or recording of the patient table position, time-resolved recording of projections of at least one part of an examination object moving with the table, the number of the slices contributing to the recording being varied during the at least one phase of variable speed of the patient table as a function of the table speed in such a way that the quotient formed from the current table speed divided by the number of the slices contributing to the recording is constant so that the pitch factor is kept constant during the projection recording, and time-resolved determination or recording of the number or slices contributing to the projection recording.

Abstract: Methods for computed tomography data-based cycle estimation and four-dimensional reconstruction are provided. A gated reconstruction is derived from CT data acquired without gating using an added artificial trigger. The resulting images for different slices are used to determine local or slice variations over time. The local variations over time for the various slices are combined to create a respiratory cycle signal. This respiratory cycle signal is used to bin the images for different phases, allowing four-dimensional CT reconstruction.

Abstract: A computer tomograph, a method, and a computer program product are disclosed. A computer tomograph is disclosed for scanning an image of at least one examination region of a patient, including a scanning unit which can be rotated about a longitudinal axis. The scanning unit includes an X-ray detector and an X-ray emitter. The extension of an X-ray beam emitted by the X-ray emitter is controlled for scanning purposes along the longitudinal axis using at least one patient-dependent control signal. By controlling the extension of the X-ray beam, the dose applied to the patient is also controlled such that the dose can be used as efficiently as possible. The control further allows the pitch to be matched to the patient-dependent control signal while scanning in the spiral mode.

Abstract: A method, a computer program, a computer program product and a computed tomography system are disclosed. The image data is a spatially three-dimensional reconstruction. At least one value for an image metric of the image data is determined. A motion field for motion compensation of the image data is then determined on the basis of image data as a function of the image metric. Essentially, partial image data is determined, wherein the partial image data corresponds in each case to the spatially three-dimensional reconstruction from scan data of an angular sub-range. The motion field of the image data is determined at the control points via an optimization method as a function of the image metric, so that, thereafter, the partial image data is transformed in accordance with the motion of the motion field. New image data is then produced by merging the partial image data.

Abstract: In an embodiment, a method includes at least moving a patient table through a measurement region of the computed tomography device, the movement of the patient having at least one phase of variable speed during the projection recording, time-solved determination or recording of the patient table position, time-resolved recording of projections of at least one part of an examination object moving with the table, the number of the slices contributing to the recording being varied during the at least one phase of variable speed of the patient table as a function of the table speed in such a way that the quotient formed from the current table speed divided by the number of the slices contributing to the recording is constant so that the pitch factor is kept constant during the projection recording, and time-resolved determination or recording of the number or slices contributing to the projection recording.

Abstract: A method is used to determine motion of an examination region of a patient. It is based on the use of a flat antenna arrangement, including at least one transmit unit and several receive units, as well as on the use of the transmit unit actuated by a control signal for the transmission of radar signals in the direction of the examination region, and the use of receive units for the receipt of radar signals reflected by the examination region. The method further includes the read-out of receive signals from the receive units, with the receive signals corresponding to the radar signals received. The assignment of the radar signals received to the transmit unit which transmitted the radar signals received in each case, by correlating the receive signals to the control signal, advantageously makes possible the adjustment of parameters derived from the correlated receive signals to retrievably stored model data.

Abstract: A radar system, a medical diagnostic or therapeutic device and a method are disclosed for operating a radar system. An embodiment of the radar system includes an antenna arrangement embodied to be flat including individually actuatable transmit units for the transmission of radar signals and individually readable receive units for the receipt of radar signals. The transmit units and the receive units each include at least one antenna. Because the transmit units can be individually actuated and the receive units can be individually read out, the information content which can be obtained even without a strong spatial orientation of the radar beam, is increased. According to an embodiment of the invention, the radar system is designed to assign a radar signal received by a receive unit to the transmit unit which transmitted the radar signal received.

Abstract: A method for reconstructing picture data of a cyclically-moving object from measurement data is disclosed, with the measurement data being detected beforehand for a relative rotational movement between a radiation source of a computed tomography system and the object under examination during a plurality of movement cycles of the object under examination. In at least one embodiment, a first picture and a second picture are determined from the measurement data, with measurement data of different movement cycles being combined for reconstruction of the second picture into a measurement dataset to be used as the basis for the picture reconstruction. Difference information is computed by comparing the first picture with the second picture. Using the difference information, a result picture is computed from the first picture and the second picture.

Abstract: A method is disclosed for x-ray CT scanning with a dual-source system, in which two radiation bundles are each delimited by diaphragms such that these radiation bundles are free of mutual points of intersection at least in the examination object. An embodiment of the invention also relates to a dual source CT system, including a controller configured to control radiation-delimiting diaphragms, which delimit and align the radiation bundles such that these run free of mutual points of intersection at least in the examination object.

Abstract: A method is disclosed for reconstructing image data of a moving examination object from measured data, the measured data having been acquired during a rotating movement of a radiation source of a computed tomography system around the examination object. In at least one embodiment, first image data are determined from the measured data. Movement information is determined from the first image data by forming the difference between images. Time instants of little movement of the examination object are determined from the movement information, the determined time instants being dependent on the location or site within the examination object. Finally, second image data are reconstructed taking the determined time instants into account. These data can be output as result images.

Abstract: An embodiment of the invention relates to a method and to a CT device for computer tomographic spiral scanning of a patient in the region of a moving organ, in particular a beating heart, wherein a pitch is adjusted which is less than the maximum pitch, with which 180° image data can still be reconstructed. In at least one embodiment, during the scan the evaluated detector data with respect to its z width and position on the at least one irradiated detector are restricted as a function of the projection angle in such a way that an effective virtual detector with smaller z width and with a z speed profile, which differs from the z speed profile of the real detector, is produced respectively, and the moving organ is reconstructed on the basis of the detector data of the at least one virtual detector.

Abstract: A method is disclosed for scanning a cyclically moved examination object using a contrast agent within the scope of a preliminary examination by way of a CT scanner, in which measurement data is recorded at a sequence of recording times. A first image is reconstructed at every recording time from the measurement data, from which a time profile of a concentration of the contrast agent is established. The recording times for respectively recording a certain phase of the motion are synchronized with a motion signal from the examination object. A second image with a time offset with respect to the first image is reconstructed from the measurement data at each recording time. A motion curve representing a time profile of an intensity of the cyclical motion is established by comparing the first image and the second image at each recording time.

Abstract: A method is disclosed for assisting in determination of the suitability of a patient for a scan of the heart of the patient using an X-ray computer tomograph. In at least one embodiment of the method, a) an electrocardiogram of the patient is recorded; b) the electrocardiogram is evaluated by predicting the occurrence time of at least the immediately following R wave on the basis of at least four immediately consecutive R waves of the electrocardiogram which were measured last, and comparing this with the actual measured occurrence time of the next R wave; and c) wherein the quality of the prediction is visualized qualitatively. Further, in at least one embodiment, a device is disclosed including an ECG instrument and a computation device for carrying out the method. At least one embodiment of the invention furthermore relates to a method and a device for scanning the heart of a patient on the basis of a prediction of R waves.

Abstract: A method is disclosed for the reconstruction of picture data of a moving object under examination from measurement, with the measurement data having been recorded beforehand for a relative rotational movement between a radiation source of a computed tomography system and the object under examination. In at least one embodiment, first picture data is computed from a complete measurement dataset of the measurement data for a picture reconstruction, and second picture data is computed from an incomplete measurement dataset for a computed tomography picture reconstruction. The first picture data and the second picture data are combined into third picture data, with the combination being computed using location-dependent movement information of the object under examination.

Abstract: The apparatus of at least one embodiment includes an input unit, a storage unit, an output unit, and an interface to the imaging device, via which configuration parameters of the imaging device can be read out or transferred. A calculating unit either reads out the configuration parameters from the imaging device or sends the configuration parameters to the imaging device if they have been entered at the input unit by an operator, the configuration parameters being required for the purpose of specifying the quantity of a contrast medium. The calculating unit is so designed as to calculate, on the basis of the parameters that have been entered and/or read out and calculation formulas which are stored in the storage unit, the quantity of a contrast medium that is required for these parameters, and to display the quantity via the output unit.

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 is disclosed for reconstructing image data of an examination subject from measured data, wherein a series of measured data sets has previously been acquired during a relative rotational movement between a radiation source of a computed tomography system and the examination subject and the measured data sets relate to the same section of the examination subject at succeeding instants in time. In at least one embodiment, first image data is reconstructed in each case from the measured data sets such that a series of first image data is available. A change variable indicating a change over time within the series of first image data is determined, and a distinction is made between different components of the examination subject in the first image data with the aid of the change variable. This distinction is used for beam hardening correction in an iterative algorithm for calculating enhanced image data.

Abstract: A method and a CT system are disclosed for predicting specific cardiac cycle phases within the scope of a CT examination, wherein signal profiles of the heart are continuously recorded during the examination over a plurality of cardiac cycles, wherein times of successive cycle positions with the same characteristics are determined with the aid of the signal profiles and the successive cycle lengths of the cardiac cycles are determined with the aid of the determined times, wherein typical patterns in successive cycle lengths over a first number of past and successive cardiac cycles are sought after and a current or future cycle length is determined by recording cycle patterns in a second, smaller number of cycle lengths including their typical successive cycle length within the first number of current past cycle lengths, and predicting, using probabilistic methods, the cycle length that follows the last determined cycle pattern on the basis of the cycle patterns currently determined during the CT examination.

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.