Abstract: A method is proposed for segmenting a brain image into a CSF region, a WM region and a GM region. An upper limit for the intensity values of a CSF region in the image is estimated such that the points of the image having an intensity less than this upper limit include a subset of the points which form a spatially connected group and which have a peaked intensity distribution. In other words, the invention exploits both the expected spatial distribution and expected intensity distribution of the CSF region. This makes it possible for the method to provide reliable discrimination of the CSF region even in CT images with poor image quality. Various methods are proposed for using the upper limit, and for improving the segmentation accuracy.

Abstract: A method for identifying a pathological region of a scan (such as a stroke region within a MRI DWI volume scan) is proposed. A region of the scan which is likely to contain pathological tissue (e.g. infracted tissue) is identified by obtaining a parameter which, for a given slice, or portion of a slice, characterizes the distribution of the intensity of pixels, e.g. the relative proportion of high intensity pixels. In a first case, such a parameter is used to identify those slices of a volume scan which are likely to include infarction. In a second case, such a parameter (hemisphere parameter) is obtained for each of the left- and right-hemispheres of a brain, to estimate which hemisphere contains the stroke. In either case, the parameter may be calculated based on ranges, percentiles and functions of the percentiles of the intensity distribution. These ranges, percentiles and functions of the percentiles are not pre-defined but are selected to maximize sensitivity.

Abstract: A method is proposed for segmenting a brain image into a CSF region, a WM region and a GM region. An upper limit for the intensity values of a CSF region in the image is estimated such that the points of the image having an intensity less than this upper limit include a subset of the points which form a spatially connected group and which have a peaked intensity distribution. In other words, the invention exploits both the expected spatial distribution and expected intensity distribution of the CSF region. This makes it possible for the method to provide reliable discrimination of the CSF region even in CT images with poor image quality. Various methods are proposed for using the upper limit, and for improving the segmentation accuracy.

Abstract: A method of estimating the location of the anterior and posterior commissures in a brain scan image is proposed. Firstly, a geometrical object is constructed using points on a brain scan image of an individual which are on the surface of the brain, such as an ellipse fitting the cerebral surface of a sagittal image of the mid-sagittal plane, or an adjacent sagittal plane. The locations on the MSP of the AC and PC landmarks (and optionally other landmarks) are estimated using the five parameters which define the ellipse, plus numerical values obtained in advance from statistical analysis of other individuals.

Abstract: Brain images are processed and analyzed with the aid of a computer for stroke diagnosis or therapeutic decision making, where multiple stroke-related images are superimposed. The superimposed images include brain images that have infarct and penumbra regions, and patient-specific brain atlas images. The infarct and penumbra regions are determined and delineated on the superimposed images. Each patient-specific brain atlas image may be formed by mapping a pre-existing brain atlas to a co-ordinate system in which the brain images are co-registered. A brain atlas may depict brain structures such as anatomy structures, blood supply territories (BST), or cerebral vasculature. The superimposed images may be used to determine any overlap between a particular brain structure and the infarct and penumbra regions.

Abstract: A method for identifying a pathological region of a scan (such as a stroke region within a MRI DWI volume scan) is proposed. A region of the scan which is likely to contain pathological tissue (e.g. infracted tissue) is identified by obtaining a parameter which, for a given slice, or portion of a slice, characterises the distribution of the intensity of pixels, e.g. the relative proportion of high intensity pixels. In a first case, such a parameter is used to identify those slices of a volume scan which are likely to include infarction. In a second case, such a parameter (hemisphere parameter) is obtained for each of the left- and right-hemispheres of a brain, to estimate which hemisphere contains the stroke. In either case, the parameter may be calculated based on ranges, percentiles and functions of the percentiles of the intensity distribution. These ranges, percentiles and functions of the percentiles are not pre-defined but are selected to maximise sensitivity.

Abstract: A system for analysing a brain image compares the image with a brain atlas, labels the image accordingly, and annotating the regions of interest and/or other structures. This atlas-enhanced data is written to a file (or more than one file) in the Dicom format or any web-enabled format such as SGML or XML format. The image used may be produced by any medical imaging modality. A fast algorithm is proposed for a landmark-based piecewise linear mapping of one volumetric image into another volumetric image. Furthermore, a new set of brain landmarks are proposed, and algorithms for the automatic identification of these landmarks are formulated for three orientations, axial, coronal, and sagittal.

Abstract: The present invention proposes a method for calculating, presenting, and combining probabilistic functional maps (PFMs) of the human brain representing the probability of structures existing. The method comprises three major steps: reading of data containing the coordinates of contacts, calculating the PFMs, and presenting the PFMs. The data can be read from a file in text or binary format or from a database as local or remote client. The PFM calculation comprises the following steps: forming 3D models of contacts, normalizing the contact models, voxelizing the contact models, calculating an atlas function, and calculating the PFM. The PFM can be presented alone or along with anatomical atlases. Both 3D and 2D interfaces can be used for presentation. The proposed method also includes different ways of combining the contact data and/or existing PFMs from multiple sources. This mechanism is the basis of an internet portal for stereotactic and functional neurosurgery.

Abstract: A technique for detecting and localising vascular occlusions in the brain of a patient is presented. The technique uses volumetric angiographic data of the brain. A mid-sagittal plane and/or lines is/are identified within the set of angiographic data. Optionally, the asymmetry of the hemispheres is measured, thereby obtaining an initial indication of whether an occlusion might be present. The angiographic data is mapped to pre-existing atlas of blood supply territories, thereby obtaining the portion of the angiographic data corresponding to each of the blood supply territories. For each territory (including any sub-territories), the asymmetry of the corresponding portion of the angiographic data about the mid-sagittal plane/lines is measured, thereby detecting any of the blood supply territory including an occlusion. The angiographic data for any such territory is displayed by a three-dimensional imaging technique.

Abstract: A 3D image may be segmented based on one or more intensity thresholds determined from a subset of the voxels in the 3D image. The subset may contain voxels in a 2D reference slice. A low threshold and a high threshold may be used for segmenting an image, and they may be determined using different thresholding methods, depending on the image type. In one method, two sets of bordering pixels are selected from an image. A statistical measure of intensity of each set of pixels is determined. An intensity threshold value is calculated from the statistical measures for segmenting the image. In another method, the pixels of an image are clustered into clusters of different intensity ranges. An intensity threshold for segmenting the image is calculated as a function of a mean intensity and a standard deviation for pixels in one of the clusters. A further method is a supervised range-constrained thresholding method.

Abstract: Brain images are processed and analyzed with the aid of a computer for stroke diagnosis or therapeutic decision making, where multiple stroke-related images are superimposed. The superimposed images include brain images that have infarct and penumbra regions, and patient-specific brain atlas images. The infarct and penumbra regions are determined and delineated on the superimposed images. Each patient-specific brain atlas image may be formed by mapping a pre-existing brain atlas to a co-ordinate system in which the brain images are co-registered. A brain atlas may depict brain structures such as anatomy structures, blood supply territories (BST), or cerebral vasculature. The superimposed images may be used to determine any overlap between a particular brain structure and the infarct and penumbra regions.

Abstract: The invention provides a system for virtually designing a medical device conformed for use with a specific patient. Using the system, a three-dimensional geometric model of a patient-specific body cavity or lumen is reconstructed from scanned volume images such as obtained x-rays, magnetic resonance imaging (MRI), computer tomography (CT), ultrasound (US), angiography or other imaging modalities. Knowledge of the physical properties of the cavity/lumen is obtained by determining the relationship between image density and the stiffness or elasticity of tissues in the body cavity or lumen and is used to model interactions between a simulated device and a simulated body cavity or lumen.

Abstract: In one aspect, the present invention provides a method of interacting with simulated three-dimensional objects, the method including the steps of the identification of three-dimensional objects from volume images; the association of physical properties with identified objects said properties including at least visual and haptic properties of the identified objects; and incorporating said identified objects and associated physical properties into a system including at least one visual interface device and at least one haptic interface device thus enabling the system to simulate visual and haptic properties of the identified objects, or any part thereof, to a human user interacting with the simulated three-dimensional objects, or any part thereof, said interaction including the generation of signals by the system for transmission to the at least one visual interface device in accordance with the physical properties associated with the objects and the reception of signals from the least one haptic interface devi

Abstract: A method for retrieving medical images from at least one image archive and creating at least one teaching file; the method including the steps of retrieving at least one medical image from the image archive; storing the at least one medical image in a database; generating a database record for the teaching file; generating the teaching file; saving the teaching file into the database; and generating at least one index of the teaching file.

Abstract: The present invention proposes a method for calculating, presenting, and combining probabilistic functional maps (PFMs) of the human brain representing the probability of structures existing. The method comprises three major steps: reading of data containing the coordinates of contacts, calculating the PFMs, and presenting the PFMs. The data can be read from a file in text or binary format or from a database as local or remote client. The PFM calculation comprises the following steps: forming 3D models of contacts, normalizing the contact models, voxelizing the contact models, calculating an atlas function, and calculating the PFM. The PFM can be presented alone or along with anatomical atlases. Both 3D and 2D interfaces can be used for presentation. The proposed method also includes different ways of combining the contact data and/or existing PFMs from multiple sources. This mechanism is the basis of an internet portal for stereotactic and functional neurosurgery.

Abstract: A method for retrieving medical images from at least one image archive and creating at least one teaching file; the method including the steps of retrieving at least one medical image from the image archive; storing the at least one medical image in a database; generating a database record for the teaching file; generating the teaching file; saving the teaching file into the database; and generating at least one index of the teaching file

Abstract: This invention provides a system and method for computer simulation of image-guided diagnostic and therapeutic procedures such as vascular catheterization, angioplasty, stent, coil and graft placement, embolotherapy and drug infusion therapy. In a particularly preferred aspect, the system is configured to resemble a cardiovascular catheterization laboratory where interventional radiology procedures are performed. A first user can interactively manipulate therapeutic catheters, guidewires and other medical devices in real-time while viewing patient-specific medical image data sets in a manner similar to that encountered in a clinical procedure.

Abstract: The invention provides a system for virtually designing a medical device conformed for use with a specific patient. Using the system, a three-dimensional geometric model of a patient-specific body cavity or lumen is reconstructed from scanned volume images such as obtained x-rays, magnetic resonance imaging (MRI), computer tomography (CT), ultrasound (US), angiography or other imaging modalities. Knowledge of the physical properties of the cavity/lumen is obtained by determining the relationship between image density and the stiffness or elasticity of tissues in the body cavity or lumen and is used to model interactions between a simulated device and a simulated body cavity or lumen.