Abstract: The invention relates to a system (100) for registering a vessel model with an image data set based on a joined model comprising a reference object model and the vessel model, the system comprising: a placement unit (110) for placing the joined model in a space of the image data set, thereby creating a placed joined model comprising a placed reference object model and a placed vessel model; a computation unit (120) for computing a deformation field based on a landmark displacement field comprising displacements of landmarks of the placed reference object model relative to corresponding landmarks in the image data set; a transformation unit (130) for transforming the placed joined model using the deformation field, thereby creating a transformed joined model comprising a transformed reference object model and a transformed vessel model; and a registration unit (140) for registering the transformed vessel model with the image data set based on modifying the transformed vessel model and optimizing an objective f

Abstract: The invention relates to a device and a method for displaying a vessel (2) with the aid of intravascular ultrasound images (I). 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, I2, I3) 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: In three-dimensional X-ray imaging, with C-arm systems, scan setup has to be performed manually under fluoroscopic control. According to an exemplary embodiment of the present invention, a scan planning system for planning a data acquisition process is provided, which is adapted to predict a field of view to be reconstructed and an image quality in the field of view with respect to the actual three-dimensional scan parameter set and previously acquired images or other information. The scan planning system may be accomplished by a stand control unit.

Abstract: The invention relates to a method and an image processing system (20) for the evaluation of projection images (25) generated by an X-ray imaging system (10), wherein the images (25) may show different instruments (51, 52) of a given set of interventional instruments like catheters or guide wires. The instruments are equipped with markers such that their configuration is characteristic of the corresponding instrument (51, 52). Preferably three markers are arranged on a straight line, the ratio of the distances between them being characteristic for the corresponding instrument. The image processing system (20) may then identify the instruments (51, 52) present in a given projection (25) and provide functionalities for a user that correspond to said instruments. Moreover, the system may be used to locate an instrument (51, 52) of interest in a projection image (25) if the marker configuration of that instrument (51, 52) is known a priori.

Abstract: method A first image of a moving object is acquired by of a first imaging method, e.g by PET or SPECT imaging. The first image contains artifacts caused by object motion. From two further images acquired by a second imaging method, e.g. C.T. or M.R., and representing the object in respective states of motion, a motion model is formed. The information contents of either the first image or a combination image, formed from the first image and the two further images, and the motion model is enhanced.

Abstract: Diagnostic angiograms only provide the projected lumen of a coronary, which is only an indirect measure of blood flow and pressure decline. According to an exemplary embodiment of the present invention, a motion compensated determination of a flow dynamics and a pressure decline for stenosis grading is provided, in which the motion compensation is performed on the basis of a tracking of a first position of a first marker and a second position of a second marker in the projection data set. This may provide for a robust and precise flow dynamics and pressure decline determination.

Abstract: The invention relates to the adaptation method (200) of adapting a geometric model to an image data comprising a region selection step (230) for selecting a region of the geometric model and a manual adaptation step (235) for manually adapting the geometric model to the image data using a set of characteristics of the region comprised in the geometric model. Using a region-specific characteristic from the set of characteristics of the selected region, such as a region-specific parameter determining the deformation range, for manually adapting the geometric model to the image data, requires relatively fewer user interactions.

Abstract: The invention relates to a device for adjusting imaging parameters of an X-ray apparatus (1), whereby a user pre-defines on a preliminary image an image region of interest (ROI) and a value of the contrast-to-noise ratio (CNRref) desired for this image region. Based on the current contrast-to-noise ratio (CNRm), new imaging parameters (I, V, L, f, Q0) are then calculated for a generator-control module (7) to control the X-ray apparatus (1) during an image. By means of the method, the X-ray dose may be reduced to a minimum, while at the same time the desired visibility of a region of interest is ensured.

Abstract: The invention relates to a method (100) of adapting a geometric model to an image data comprising determining a first partial transformation for mapping a first part of the geometric model into the image data and a second partial transformation for mapping a second part of the geometric model into the image data. By determining the first partial transformation of the first part of the geometric model and the second partial transformation of the second part of the geometric model, the geometric model can assume more shapes and therefore can be more accurately adapted to an object comprised in the image data.

Abstract: The invention relates to a method (100) of and to a system (200) for determining a template mesh of a shape model on the basis of a plurality of instances of the shape model. The method of determining the template mesh of the shape model comprises an obtaining step (110) for obtaining the plurality of instances of the template mesh, a computing step (120) for computing a plurality of results on the basis of the plurality of instances of the shape model, a deciding step (130) for deriving a decision on the basis of the plurality of results, and a decimating step (140) for decimating the template mesh of the shape model on the basis of the decision, thereby determining the template mesh of the shape model. Thus, the template mesh of the shape model determined by the method of the invention better describes objects of interest at all locations.

Abstract: A method allowing display of time-varying merged high resolution and low resolution image data with a smooth frame rate. In one embodiment the high resolution data is structural image data and the low resolution image data is functional image data. The functional image data is gathered (20) into groups and each group is rendered and merged (24) together. The merged images produced are then stored (28) in a First In First Out (FIFO) buffer for display. While the merged images are displayed the next set of functional image data is merged and rendered and supplied to the FIFO buffer, allowing a smooth frame rate to be achieved. A computer program and a medical imaging apparatus using the method are also disclosed.

Abstract: A system, apparatus and method are provided for measuring and removing the influence of pulsatility on contrast agent flow in a region of interest of a vascular system of a patient. Once the change of blood speed over the cardiac cycle is known (pulsatility), this influence is removed from acquired image sequence for outcome control such that “quasi-stationary”, regular flow acquisition is passed on to subsequent visualization and analysis processes. A contrast agent injector is also provided that simultaneously measures and uses ECG to inject a known contrast agent at a fixed point over the cardiac cycle or such that a known amount of contrast agent will arrive at a known time at a region of interest in the vasculature of a patient, thus controlling one of the main unwanted variables in an acquisition of blood flow sequences.

Abstract: Method and system for facilitating post-processing of images using deformable meshes in which a deformable mesh model of an object such as an organ is extended by attaching information thereon in order to simplify and/or facilitate a desired post-processing task so that the post-processing task effected when the mesh is applied to the same object in an additional image can expeditiously use this information. The information may be attached to the mesh after its creation, for example, upon segmentation of the same object in some training image. The post-processing task can therefore be performed automatically without user interaction upon segmentation of the object in the additional image. Information is encoded on the mesh by enumerating a list of triangles or vertices of the mesh which have to be considered in the subsequent, post-processing task and by optionally providing additional parameters defining the precise post-processing algorithm(s) to be used.

Abstract: A system (900), method (100, 200) and apparatus (600, 700, 800) are provided for analyzing a blood flow in a vascular system from a dynamic diagnostic observation sequence (101) to determine blood flow parameters (112) for further determination of filters, replay speed and finally visualization of the replayed original and filtered sequences. A first embodiment (100) extracts features of the observation and uses these features to select an appropriate model from a database of pre-determined models of vascular system of interest which have associated parameters. These parameters are varied to create an instance of the model that best matches the original observation. A second embodiment (200) visualizes a replay of the original observation (101) and the observation (101?) predicted by the model to highlight differences therebetween. A third embodiment (800) provides filtering and control of the replay speed.

Abstract: There is described a method for generating a 2-D image of a 3-D object represented by a volume data set comprising a multiplicity of data points each having an opacity value. A plurality of notional rays are cast through the 3-D object and for each ray, a ray path is divided into a plurality of base sampling intervals defined by data points on the path. If it is determined that a difference in opacity values across a base sampling interval can become greater than a pre-determined value, successively smaller sampling regions are generated within the base sampling interval until it is determined that a difference in opacity values across each generated smaller sampling interval in the base interval is less than the pre-determined threshold. Values indicative of an interaction between the ray and the 3-D object in the sampling intervals along the path are accumulated using a direct volume rendering procedure to determine a pixel value in the 2-D image.

Abstract: Deformable models are used for the segmentation of structures in 3D images. The basic principle of such methods consists of the adaptation of flexible meshes to the image. However, the simultaneous segmentation of multiple or composed objects often causes problems in that spatial relationships between the objects are violated, or that meshes are intersecting each other. According to the present invention, a priori knowledge about spatial relationships between objects is introduced into the shaped model. This allows to maintain spatial relationships between the objects and to avoid intersecting meshes.

Abstract: Adaptively controlling an imaging system (200, 205) includes constructing model feature characteristics (105) of a process over time, determining parameters and commands (110) for controlling the imaging system for each state of the process, performing data acquisition (120) for the process, extracting current features (130) of the process from the acquired data, matching (135) the current features (130) with the model feature characteristics (105) to determine a state of the process (140), and controlling the data acquisition based on the state of the process to produce optimized data.

Abstract: The present invention relates to an apparatus for determining an injection point for targeted drug delivery into a patient's body by injection of the drug into a vessel feeding a target area including a target. To provide the interventionalist with an objective and quantitative assessment of potential drug injection points instead of letting him rely on his subjective impression from the visual inspection of DSA sequences, an apparatus is proposed comprising: identification means (41) for identification of a vessel tree topology of vessels feeding said target area, flow determination means (42) for determining the percentage of drug material delivered to said target after injection into different potential injection points in said vessel tree, selection means (43) for selecting as optimal injection point the potential injection point resulting in the highest percentage of drug delivery to said target.

Abstract: The invention relates to a method and a system for the simultaneous reconstruction of the three-dimensional vessel geometry and the flow characteristics in a vessel system. According to one realization of the method, vessel segments (41) of a parametric models are fitted to differently oriented X-ray projections (Pl, Pk, PN) of the vessel system that are generated during the passage of a bolus of contrast agent, wherein the fitting takes the imaged contrast agent dynamics and physiological a priori knowledge into account. In an alternative embodiment, the vessel geometry is reconstructed progressively along each vessel, wherein a new segment of a vessel is added based on the continuity of the vessel direction, vessel radius and reconstructed contrast agent dynamics.

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).