Abstract: The present invention discloses an analysis method and system for detecting vascular structures at arterial, capillary, and venous phases from time-series digital subtraction angiographic images. The method comprises the steps of: acquiring a time-series dataset of a subject using at least one rotating x-ray source and detector pair; administrating a contrast media to a blood vessel of the subject during the data acquisition; applying a motion artifact correction to the time-series dataset; and applying a segmentation method to the time-series dataset for identifying vascular structures with different flow patterns of the contrast media. The invention offers the potential to efficiently provide quantitative flow changes inside the clinical operation room without manual selection and motion artifact error.

Abstract: The present invention discloses a method and apparatus for measuring AIF and VOF on brain perfusion CT images. The AIF and VOF are used to calculate hemodynamic parameters. In this invention, bone voxels and neighboring voxels are removed first from the perfusion images and thus only brain voxels are included in the AIF and VOF measurement procedures; moreover, the selection criteria, such as large area under the concentration-time curve, early arrival of contrast agents, and narrow effective width, are used to select appropriate arterial and venous voxels for the AIF and VOF measurements.

Abstract: The present invention discloses a method and apparatus for brain perfusion magnetic resonance imaging (MRI) technique with the removal of cerebrospinal fluid (CSF) pixels. This invention utilizes a CSF/brain-contrast-enhanced image, wherein the CSF/brain-contrast-enhanced image is defined as the signal difference between CSF and brain matter divided by a standard deviation of air background random noise is larger than 3, acquired from the subject's brain, and applies a segmentation technique to remove the CSF pixels. After removing the CSF pixels on parametric images, the extent of brain tissue with delayed perfusion can be better identified. By using a good region of interest enclosing the correct delayed-perfusion region, the measurement on the tissue volume and perfusion parameters would be more accurate than the area contaminated by CSF pixels.

Abstract: The present invention discloses a method and apparatus for brain perfusion magnetic resonance imaging (MRI) technique with the removal of cerebrospinal fluid (CSF) pixels. This invention utilizes a CSF/brain-contrast-enhanced image, wherein the CSF/brain-contrast-enhanced image is defined as the signal difference between CSF and brain matter divided by a standard deviation of air background random noise is larger than 3, acquired from the subject's brain, and applies a segmentation technique to remove the CSF pixels. After removing the CSF pixels on parametric images, the extent of brain tissue with delayed perfusion can be better identified. By using a good region of interest enclosing the correct delayed-perfusion region, the measurement on the tissue volume and perfusion parameters would be more accurate than the area contaminated by CSF pixels.

Abstract: A method is provided for processing perfusion images of an anatomy of a subject, which were acquired at different times using dynamic susceptibility contrast magnetic resonance imaging after injecting the subject with a contrast agent. The method includes: (a) applying blind source separation to separate the perfusion images into a set of blind source separated images; (b) setting thresholds for the blind source separated images to generate a set of mask images; (c) using the mask images as an initial guess and applying a segmentation technique to generate segmented images; and (d) measuring signal-time curves on the perfusion images using the segmented images. A computer program product including a computer-readable storage medium that contains a computer program for executing the steps of the image processing method is also disclosed.

Abstract: A method for correcting striation artifacts that are generated during a magnetic resonance imaging method. The method involves generating an image of a body area. The image is reconstructed from raw data collected in a spatial-frequency domain. As some of the data points in the raw data from which the image is generated are corrupted, the image of the body area contains striation artifacts. A region containing a homogenous material is selected. Next, the corrupted data points in the raw data are detected and corrected vis-a-vis a Fourier transform correction process, and a new corrected image essentially free of striation artifacts is generated.

Abstract: An NMR system performs a dual-echo fast-spin-echo scan to acquire two NMR data sets from which proton density-weighted and T.sub.2 -weighted images may be reconstructed. The two NMR data sets are combined to produce a composite NMR data set from which a black blood NMR angiogram is produced by a minimum intensity projection.

Abstract: A dual echo magnetic resonance imaging system produces two registered images of a patient in which the images have different contrast relationships between different tissue types. A two dimensional feature space histogram of the two images is produced and a separate centroid is located in the feature space histogram for each one of a pair of tissue types. A Cartesian coordinate system is defined in the feature space so that one axis of the system passes through the two centroids. Vector decomposition is employed to project each image element data point in the feature space onto a point on the one axis. The fractional quantity of each tissue type present in the image element is determined based upon the Euclidean distances from that axis point to the respective centroids. The fractional quantity is calculated for each element in the original images to form a pair of tissue images. The elements of a tissue image are processed to measure the amount of that tissue type in the imaged portion of the patient.