Abstract: A radiation therapy planning procedure and device provides a model-based segmentation of co-registered anatomical and functional imaging information to provide a more precise radiation therapy plan. The biology-based segmentation models the imaging information to produce a parametric map, which is then clustered into regions of similar radiation sensitivity or other biological parameters relevant for treatment definition. Each clustered region is prescribed its own radiation prescription dose.

Abstract: A therapy system (100) includes an imager (102), a therapy planner (104), and a therapy device (106). The therapy planner (104) includes a therapy prescription apparatus (118) which calculates a desired therapy (D) to be applied to a human patient or other subject. The therapy prescription system (118) uses a pathology model (122) and a patient-specific biological parameter history (124) to optimize the applied therapy.

Abstract: A method for use in functional medical imaging includes adaptively partitioning functional imaging data as a function of a spatially varying error model. The functional image data is partitioned according to an optimization strategy. The data may be visualized or used to plan a course of treatment. In one implementation, the image data is partitioned so as to vary its spatial resolution. In another, the number of clusters is varied based on the error model.

Abstract: An imaging system (10) comprises a data device (30), which controls radiation data acquisition from a subject positioned in an examination region (18) for an examination. A rebinning processor (40) bins the acquired data periodically into a histogram (42). A transform (70) transforms the histogram (42) into individual independent or uncorrelated components, each component including a signal content and a noise content. A stopping determining device (52) compares an aspect of at least one selected component to a predetermined threshold (TH) and, based on the comparison, terminates the data acquisition.

Abstract: An improved radiation therapy planning procedure is suggested. The procedure comprises the steps of specifying and determining the absolute grade of cell degeneracy by in-vitro tests, whereby marker(s) indicative for specific cell degeneracy are detected and quantified, establishing a biology-based segmentation of areas with similar grade of relative cell degeneracy and applying the absolute grade of cell degeneracy to the biology-based segmentation data, thereby establishing an improved radiation therapy planning procedure.

Abstract: A radiation therapy planning procedure and device provides a model-based segmentation of co-registered anatomical and functional imaging information to provide a more precise radiation therapy plan. The biology-based segmentation models the imaging information to produce a parametric map, which is then clustered into regions of similar radiation sensitivity or other biological parameters relevant for treatment definition. Each clustered region is prescribed its own radiation prescription dose.

Abstract: A reconstruction processor (34) reconstructs acquired projection data (S) into an uncorrected reconstructed image (T). A classifying algorithm (66) classifies pixels of the uncorrected reconstructed image (T) at least into metal, bone, tissue, and air pixel classes. A clustering algorithm (60) iteratively assigns pixels to best fit classes. A pixel replacement algorithm (70) replaces metal class pixels of the uncorrected reconstructed image (T) with pixel values of the bone density class to generate a metal free image. A morphological algorithm (80) applies prior knowledge of the subject's anatomy to the metal free image to correct the shapes of the class regions to generate a model tomogram image. A forward projector (88) forward projects the model tomogram image to generate model projection data (Smodel). A corrupted rays identifying algorithm (100) identifies the rays in the original projection data (S) which lie through the regions containing metal objects.

Abstract: The present invention provides a system, apparatus, and method that are based on a priori knowledge of the shape of the input function for defining an input region-if-interest (ROI) in pharmacokinetic modeling. Kinetic parameter estimation requires knowledge of tracer input activity and the present invention provides an automatic way to define an ROI for estimation of an input function that takes into account a priori knowledge of the shape of the input function based on an administered dose. As a result of the application of the present invention to existing imaging analysis systems, there is a reduction in the amount of manual interaction needed and operator dependence is thereby reduced in the evaluation of dynamic procedures.

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 an imaging system for imaging an object (4), said imaging system comprising a detection unit (3) for consecutively acquiring projection data sets (Pi) of the object (4), said detection unit (3) having a temporal response function that is characterized by at least a time constant (?), a rotation unit that, while the projection data sets (Pi) are being acquired, moves the detection unit (3) around the object (4) with an essentially constant angular velocity (?), a reconstruction unit (9) for computing an image data set (13) of the object (4) from the projection data sets (Pi), and a filter unit (10) that, in an active state, applies a filter (f) on the image data set (13) to compute a correction, which filter acts as a derivative on the perturbed image, essentially in a direction corresponding to the direction of the angular velocity, is essentially proportional to the time constant (?) and is essentially proportional to the angular velocity (?), said filter unit (10) being arranged to

Abstract: The invention relates to the estimation of kinetic parameters for a target region (210) utilizing information from a normal (unperturbed) reference region (200). The proposed compartmental model models metabolic pathways for blood, reference and target tissue. The proposed analysis procedure features two alternatives: (A) Extraction of the plasma input in the reference region (200) and its unperturbed kinetic parameters, hereafter utilization of the plasma input and the kinetic parameters of the reference region as initial parameters for the analysis of the target region (210). (B) The system of kinetic equations describing the kinetics of the imaging agent in the target and reference regions is solved for the input function (amount of free imaging agent in the plasma or the total imaging agent SB(t) contained in plasma, blood elements and metabolites) considered to be the same for both regions.

Abstract: The invention relates to a data processing system (1) for the evaluation of image data, particularly of PET-images (I), that represent the time varying concentration of a tracer substance like F-MISO in an object (20). The data processing system (1) comprises a library module (48) with analytical solutions (Cj(t)) for several compartment models. Preferably the library also contains the analytical gradients with respect to the parameters of interest. From the library an appropriate solution for each study can be chosen by a user. The use of analytical functions together with the information about the error (?A(t)) of the input data (either via noise models 43 or via a simulation 44) allows to extract all parameters mandatory to fully understand the kinetics of complex models (more than one tissue compartment) on a per-voxel basis in a robust way in real-time.

Abstract: The invention relates to a method of adapting imaging parameters for a computer tomographic radiograph of a body volume, comprising the following steps: obtaining a three-dimensional pilot radiograph with a low dose of radiation (1); determining a region of interest and a desired image quality in the pilot radiograph (2) with the aid of a patient model (4) or interactively (3); determining optimal imaging parameters (5); generating an X-ray image using the determined imaging parameters (6). Optionally, the X-ray image is combined (7) with the pilot radiograph.

Abstract: In order to reduce an x-ray dose applied to a patient, it is necessary to know the dose absorbed by the patient. According to the present invention, there is provided a method of determining a local patient dose applied to a patient where after the reconstruction of the scan data into a diagnostic image, the scan data are backprojected into the patient volume, using the attenuation information of the diagnostic image to form a spatially varying photon fluence map. In parallel, the diagnostic image is segmented into anatomical structures to which dose-weighting factors are assigned. The locally absorbed dose is then calculated on the basis of the fluence map and the corresponding dose weights.