Abstract: The invention relates to the association of a current (X-ray image) image of a body volume with one of several stored previous images, the ECG and the respiratory cycle being determined each time together with the images. Using this data, that one of the previous images is chosen which is closest to the current image in respect of cardiac rhythm and respiratory cycle. The resultant association yields a very high accuracy enabling superposed reproduction of the current image and the associated previous image.

Abstract: A medical imaging system in which a current (X-ray) image (8) of a body volume is selected for association with one of several stored images (1Oa5IOb), the ECG and the respiratory cycle being determined each time together with the images. First and second static images (R1,R2) of the body volume in first and second extreme respiratory states are provided, and first and second respective similarity values (r1,r2) are determined for each current and previous image so as to calculate the respiratory phase of the body volume therein. Using this data, one of the previous images (10a) is chosen which is closest to the current image (8) in respect of cardiac rhythm and cycle.

Abstract: Linking of interventional and real time ultrasonic information with nonereal time anatomical information of, for example, a vessel or a tumor vascularization provided by x-ray rotational angiography requires high computational performance. According to an aspect of the present invention, an ultrasonic reference image is calibrated with respect to a high quality image acquired by a different imaging system. Then, during operational intervention, a registration or calibration of a data set acquired during the intervention is performed with respect to the reference image and not (as in state of the art devices) to the high quality image. Advantageously, this may allow for a fast fusion of the high quality image with the real time images and therefore allow for an improved tracking of operational interventions performed on a patient.

Abstract: An apparatus and method for ablating tissue in a heart (24) of a subject (25) during an ablation procedure is disclosed. The method includes contacting an ablation catheter tip (48) to tissue of the heart (24) at a plurality of sites designated for ablation; sensing at each respective site a feedback signal from the ablation catheter indicative of success of the intended local ablation; storing any available data defining a current position of the ablation catheter tip (48) relative to the heart (24) at a moment of sensing the feedback signal indicative of a failed intended ablation for later re-visit; displaying a map (60) of a region of interest of the heart (24); and designating, on the map display (60), indications of the sites corresponding to when the required electrical current is above the threshold current value indicative of a gap in an ablation line or ring.

Abstract: A diagnostic imaging system (10) corrects metal artifact streaks (38) emanating from a metal object (36) in a tomographic image (T). A first processor (40) reduces streaks (38) caused by mild artifacts by applying an adaptive filter (82). The filter (82) is perpendicularly oriented toward the center of the metal object (36). The weight of the filter (82) is a function of the local structure tensor and the vector pointing to the metal object (36). If it is determined that the strong artifacts are present in the image, a second processor (48) applies a sinogram completed image algorithm to correct for severe artifacts in the image. The sinogram completed image and adaptively filtered image are fused to a final corrected image. In the fusion process, highly corrupted tomographic regions are replaced by the result of the sinogram completed image and the remainder is replaced by the adaptively filtered image.

Abstract: The invention relates to a system and a method for the guidance of a catheter (20) with an electrode (21) in an electrophysiological procedure. A sequence of images (I1, . . . Ik, . . . ) of the catheter (20) and of a resting reference catheter (30) is generated with an X-ray device (10) and stored together with the associated electrographic recordings from the electrodes (21, 31). A reference image (Ik) may then be selected from said sequence that corresponds to a desired electrographic pattern (Ek). In a next step, the positions (T, R) of the catheters (20, 30) are localized on the reference image (Ik), wherein the position (R) of the reference catheter (30) can be identified with the position of this catheter (30) on an actual image (I). Thus it is possible to determine on the actual image also a target position (T? for the catheter (20) that corresponds to the position (T) of this catheter (20) on the reference image (Ik).

Abstract: In real-time three-dimensional imaging the choice of the visualization method and orientation is crucial for intervention success. The key question is what to ignore and what to show in real-time applications, where user control is not appropriate. The invention addresses this problem by visualizing an intervention (caused by a user) to an object of interest without the requirement of an interactive input by the user. Advantageously, according to an exemplary embodiment of the present invention, parameters for a visualization procedure are automatically chosen during data acquisition which may allow for an efficient tracking of the actual orientation and relative position of the structure with respect to the object of interest.

Abstract: The invention relates to a method of and a device for forming an image which is composed of a plurality of sub-areas, a read-out unit being associated with each sub-area and image data of adjoining image areas of neighboring sub-areas being evaluated in order to mitigate differences in amplification, which device includes a detector with a plurality of sensor elements for forming image data, read-out units which are associated with the sub-areas of the image, an analysis unit which is arranged to evaluate image data from adjoining image areas of neighboring sub-areas and to generate correction data, a correction unit which is arranged to correct incorrect image data by means of correction data, thus enabling a regular and accurate recalibration or correction of non-linear amplifier behavior to be performed without necessitating an additional X-ray dose or interventions by the user.

Abstract: The invention relates to a method of improving the precision of a medical nuclear SPECT or PET image in which notably a nuclear sectional image (n) can be superposed on a two-dimensional ultrasound image (u). For the superposition that nuclear sectional image (n0) which exhibits the best correspondence with a free-hand ultrasound image (u) is chosen from a three-dimensional nuclear image (2). In order to determine this sectional image, an evaluation index f(n,u) is calculated, on the basis of an estimated value (1), for differently situated nuclear sectional images (n). This index assigns a positive value to positions of structures (heart muscle tissue etc.) which correspond in the two images, a neutral value to structures which are represented only in the ultrasound image (u) and a negative value to structures which are represented only in the nuclear sectional image (n).

Abstract: The invention relates to a method of forming a very accurate vascular map or road map to be associated with the current X-ray image during an invasive vascular intervention. The vascular map is derived from a four-dimensional model of the vascular tree, that is, from a spatially three-dimensional, time-dependent model, the time dependency relating to natural motions of the body such as notably the heartbeat and/or the respiration. In particular the rhythm of the heartbeat or the respiration can be determined by means of a sensor so as to be used for synchronized selection and display of the corresponding three-dimensional vascular model.

Abstract: The invention relates to a device and a method for providing an angiographic image (A) based on a database (2) with angiograms (3, 3a) from various heartbeat phases (H) and respiratory phases (R). From the available angiograms (3, 3a), a function (f) is first calculated, which describes the position (x) of the heart (1) dependent upon the respiratory phase (R). With the aid of this function (f) an angiographic image (A) may be generated which matches the heartbeat phase (Hd) and the respiratory phase (Rd) for given values of the heartbeat phase (Hd) and the respiratory phase (Rd), by transformation of an available angiogram (3a) which matches the heartbeat phase (Hd).

Abstract: The invention relates to a device and a method for displaying a vessel (2) with the aid of intravascular ultrasound images (1). A sequence of intravascular ultrasound images (I(E,x)) is generated by means of a probe (5) and stored in a memory (10) in a manner indexed by the associated location (x) where they were generated and also the associated heartbeat phase (E) and/or breathing phase. During a subsequent medical intervention, those ultrasound images (I1,12,13) which best correspond to the heartbeat phase of a current fluoroscopic image (At) or belong to the current stopping location of a catheter (13) can be selected from the memory (10) and displayed on a monitor (12).

Abstract: During catheter or guide wire intervention, a road map of, for example, the coronary vessel tree based on pre-interventional angiograms is displayed. This road map, however, is naturally static and hence not consistent with the instantaneous heart and respiration cycles in the life image, which may be displayed on the screen next to the road map. According to an exemplary embodiment of the present invention, images of a series of x-ray images of an object of interest are determined, where the object of interest is not sufficiently filled with the contrast agent. Advantageously, these images may be used to provide for an improved road map.

Abstract: A method for reading out image points of a two-dimensional electronic image sensor includes subdivided the image into at least two different regions where the region of greater interest ROI is read at a scanning rate which is higher than that used for other regions. Consequently, the region of interest can be reproduced with a higher temporal resolution. The sensitivity of the reading unit is adapted in conformity with the scanning rate of a relevant image point so as to take into account the fact that image points that are read out less frequently collect a light intensity over a prolonged period of time and hence may reach high signal strengths. Regions that are less frequently read out can also be irradiated with a lower radiation intensity by applying appropriate masking. The method is very suitable for the imaging of time-critical processes in medical X-ray applications.

Abstract: The invention relates to a device and to a method for combining two images, especially for superimposition of static vascular maps (B), which were taken at different phases of the cardiac cycle and/or the respiratory cycle and were archived in a memory (6), on a current image (A) of a catheter (2, 8) in the vascular system (9). In the method, a defined section of a map image (B) around the estimated actual position of the catheter is selected and is displayed superimposed on the current image (A) in an image (C) on a monitor (10). The map image (B) used for this is preferably selected by means of an electrocardiogram to match the particular cardiac cycle. The position of the catheter relative to the map image (B) can be estimated using a distance image (D).

Abstract: The invention relates to a device and to a method for superimposed display of current (X-ray) image (A) of an object (8), such as a catheter for example, and a map image (B) of the vascular system. In this connection, for map images (B) archived in a memory (6) the associated distance images (D) are calculated by means of a distance transformation (A). In the current image (A) the object (8) is segmented (?). By means of the distance image (D), a transformation of the map image (B) is then calculated, so that, when the current image (A) and the transformed map image (?(B)) are superimposed on a monitor (10), the image of the object (8) lies in the path network of the transformed map image.

Abstract: The invention relates to a method and a device for automatic testing of an X-ray system (2). The doors (5a, 5b) leading to the room (1) in which the X-ray system (2) is installed are monitored by way of sensors (4a, 4b). Furthermore, the state of the room (1) can be monitored by means of further sensors such as video cameras (3). Automatic testing of the X-ray system (2) while utilizing X-rays is started only if and for as long as all doors are closed and the other sensors do not indicate that a safe state is abandoned. The device may also include facilities for automatically positioning a phantom in the beam path. Such facilities may in that case include a phantom which is provided on a flexible foil.

Abstract: In a system for driving inertia-prone picture-reproducing devices, in particular liquid-crystal displays, in which a correcting value that depends on changes in the video signals from frame to frame is added to incoming video signals to compensate for the inertial effects and in which the corrected video signals are passed to the picture-reproducing device to form the correcting value, a model of the picture-reproducing device is provided that has a state variable as an output variable, the video signals as a first input variable and the state variable from a preceding frame as a second input variable. Furthermore, to derive the correcting value, a function having the incoming video signals and the state variable of the preceding variable as input variables and the corrected video signals as an output variable.

Abstract: The invention relates to a catheter arrangement which comprises at least a first basic element and a second basic element, which second basic element is arranged such that it is slidably arranged in the first basic element over at least part of its length and has a sensor unit that is provided for determining a position and/or mutual position shift of the first basic element and the second basic element, to generate at least a sensor value that is assigned to a measurable property of the catheter arrangement. The repeated reaching of a once-defined position is allowed by such a catheter arrangement, so that after expanding a vessel constriction, a stent can be taken to the same position without having to take X-rays for verification of the position, which are burdensome to the patient.

Abstract: The invention relates to an imaging (X-ray) system for observing the motion of an object in the vascular system of a body volume (10). An X-ray apparatus (3) in this system generates two-dimensional projection images (4) of the body volume (10). In a module (5) the position of the tip of the object is determined from the projection images and this position is associated, in a further module (2), with a previously acquired three-dimensional representation (1) of the vascular system. The module (2) then calculates optimum imaging parameters which involve notably a planar projection of the tip of the object and a minimum projection window. These parameters are subsequently set on the X-ray apparatus (3) so as to serve as a basis for the next two-dimensional image (4).