Abstract: A method for determining asymmetry in an image such as an MR image of a brain comprises determining a symmetry plane to divide the image into a first part and a second part representative of, for example, the hemispheres of the brain. The probability distributions of voxels against intensities are determined for the first and second parts and histograms of intensities representative of the parts are generated. Compensation is made for any relative shift along a predetermined axis between the histograms. A divergence value based on a distance between the first and second histograms is then calculated and it is determined if the calculated divergence value is greater than a predetermined threshold. A divergence of greater than the predetermined threshold is indicative of asymmetry in the image that may be considered as suspicious for abnormality. There is also disclosed an apparatus for determining asymmetry in an image.

Abstract: A method and apparatus for identifying pathology in a brain image comprises the steps of firstly determining the location of the midsagittal plane (MSP) of the brain illustrated in the image under examination by identifying the symmetry of the two hemispheres based on the determination of up to 16 approximated fissure line segments (AFLSs). Those AFLSs with a larger angular deviation from the MSP than a predefined threshold are considered as outlier AFLSs while the rest are taken as inlier AFLSs. The ratio of the number of the outlier AFLSs to the number of inlier AFLSs is then calculated. A comparison of the ratio with a further predetermined threshold value is made and if the ratio exceeds the further predetermined threshold value, pathology is present in the brain image.

Abstract: Volumes of interest may be defined, within a three-dimensional brain image, for each of three orthogonal directions. Measures, which may, for example, be energy or entropy measures, are determined for slices of the volumes of interest in the three directions. The volume of interest corresponding to the sagittal direction is then identified. The slice, among the slices in the volume of interest corresponding to the identified sagittal direction, having the optical measure is used to define a first estimate of the mid-sagittal plane. The first estimate of the mid-sagittal plane may then be used to build an input to an optimization technique, which operates until a convergence criterion is satisfied, at which point a final estimate of the mid-sagittal plane may be produced.

Abstract: In a preferred embodiment, medical apparatus comprising a catheter (12) which operable to be inserted into a human subject (10) is disclosed herein. Haptic sensors (22, 24) and deformation sensors (26, 27) are connected to the catheter (12) and these are disposed at a plurality of locations along the length of the catheter (12). The haptic sensors measures 3D forces (18) acting on the catheter (12) at the disposed locations and these forces are provided to a haptic feedback device (14) which provides haptic feedback to, an interventional radiologist. The deformation sensors (26, 27) on the other hand, measures the deformation of the catheter (12) at the disposed locations and this information determines the shape of the catheter (12) which is represented on a display (16) for viewing by the radiologist.

Abstract: A method is proposed for binarising an image by deriving an intensity threshold and classifying pixels according to whether their intensity is below or above the threshold. In the derivation of the threshold, prior konwledge is used to define a region of interest (ROI) in the image. Furthermore, prior knowledge is used to select a range in the frequency distribution of the intensities of the pixels in the ROI, and that only data within this frequency range is used to derive the threshold. These techniques provide a highly effective mechanism for incorporating prior knowledge into the threshold selection which is critical whether the image is a medical image or not. In particular, a threshold can be found to binarise images which exhibits high robustness to imaging artefacts such a gray level inhomogeneity and noise.

Abstract: A method for retrieving medical images from various sources and in different formats, to enable the creation of teaching files and research datasets, for the building of a personal medical image library, the method comprising: retrieving a plurality of medical images from various sources; storing the plurality of medical images in a database; generating a database record for the teaching files and research datasets; generating the teaching files and research datasets file; saving the teaching files and research datasets into the database; and generating at least one index of the teaching files and research datasets.

Abstract: The AC and/or PC landmarks are identified in a midsagittal MRI image by firstly identifying structures in the brain (specifically the fornix and/or brainstem) as groups of pixels in a radiological image which have an intensity in ranges defined by one or more thresholds and which obey predefined geometrical criteria. The thresholds are varied until the predefined geometrical criteria are met. Initial estimates of the position of the AC and/or PC are derived from the identified structures. These estimates can be improved in various ways, especially by making use of axial and/or corona/radiological images in planes including, and/or proximate to, the initial estimated position of the AC and/or PC.

Abstract: The present invention discloses a method for registering a measured MRI volume image with appropriate anatomical and blood supply territory Atlases to enable Atlas information to be mapped onto the measured MRI volume image. The disclosed arrangements provide an efficient method for mapping brain Atlas information (including gross anatomy and blood supply territories) into magnetic resonance perfusion and diffusion images.

Abstract: Methods, computer systems, and computer program products for segmenting tissue based upon image data representing brain tissue are disclosed. In the method, image data representing brain tissue is reformatted to a predetermined spatial orientation. Spatial statistics relating to spatial features of the represented brain tissue are determined. The represented brain tissue is classified within categories of white matter, gray matter and cerebrospinal fluid. A region of interest in the represented brain tissue classified as cerebrospinal fluid is identified. The represented brain tissue proximate the identified region is segmented using a region-growing technique based on the identified region of interest.

Abstract: A method is disclosed for obtaining the location of a landmark in an MR image of a brain. In a first step, a region of interest in a plane within the MR image containing the landmark is defined. In a second step, the ROI is binarised into foreground and background voxels based on at least one threshold selected using anatomical knowledge. In a third step a set of object voxels is identified from the foreground voxels, excluding voxels which were only classified as object due to proximity of cortical and non-cortical structures. This can be done by morphological processing which reclassifies voxels which may have been incorrectly classified as object, followed by restoring voxels due to the partial volume effect and/or morphological erosion/opening. In a fourth step, an automatic process is then carried out to identify one or more landmarks in the modified binarised image.

Abstract: A functional model for a set of experimental data has K independent parameters. The parameters are to be estimated from an experimental data-set of N data points, comprising “inlier” data points representative of the model and “outlier” data points which are not representative of the model. Multiple subsets of the data points are defined, and each used to estimate the parameters of the model. The various estimates of the parameters are plotted in the parameter space to identify the peak parameters in the parameter space. Data points which are not described by the model using the said peak parameters are judged to be outliers. The method makes it possible to identify up to N?K??3 outliers (K? is the minimum number of data points through any subset of the input data set the K parameters of the model can be uniquely calculated).

Abstract: A method and apparatus for extracting a cerebral ventricular system from images of one or more cerebral ventricular regions comprises defining multiple regions of interest (ROI) in the images, defining seed points within each ROI, growing images of ventricular regions while correcting for leakages into extraventricular space and connecting the ventricular regions grown

Abstract: A method for extracting third ventricle information from images of a plurality of axial slices of a third ventricle of a brain comprises determining a midline for each of a number of the axial slices, determining the orientation of each of the midlines, generating a histogram of the orientations of the midlines, determining the peak of the histogram to provide a peak orientation, selecting the midlines having an orientation within a predetermined angle from the peak orientation and calculating the third ventricle plane from the midlines having an orientation within the predetermined angle from the peak orientation.

Abstract: Methods of modeling anatomical structures, along with pathology including the vasculature, spine and internal organs, for visualization and manipulation in simulation systems. A representation of on the human vascular network is built up from medical images and a geometrical model produced therefrom by extracting topological and geometrical information. The model is constructed using topological and geometrical information. The model is constructed using segments containing topology structure information, flow domain information contour domain information and skeletal domain information. A realistic surface is then applied to the geometric model, by generating a trajectory along a central axis of the geometric model, conducting moving trihedron modeling along the generated trajectory and then creating a sweeping surface along the trajectory.