Abstract: A method for processing CT colonography input image voxel data representative of 3-dimensional images of a colon having gas and stool tagged with stool tagging agent, to remove the stool from the images. The input image voxel data is generated by an imaging instrument having a characteristic point spread function representative of instrument blurring. The point spread function of the instrument can be empirically determined, and the image data processed as a function of the point spread function to accurately identify and remove the tagged stool. In one embodiment of the invention, portions of the image data representative of the tagged stool and colon tissue are dilated as a function of the point spread function.

Abstract: Systems, methods and articles of manufacture are disclosed for compensating for motion of a subject during an MRI scan of the subject. k-space data may be received from the MRI scan of the subject. A first graphical image may be generated from a first set of data elements from the k-space data. Similarly, a second graphical image may be generated from a second set of data elements from the k-space data. An offset in pixels may be determined by which to translate the second graphical image from the first graphical image to compensate for the motion. The k-space data may be modified at a sub-pixel offset relative to the determined offset. A motion-compensated graphical image of the subject may be generated from the modified k-space data. Doing so reduces the search space evaluated to sharpen images generated from the k-space data.

Abstract: Systems, methods and articles of manufacture are disclosed for compensating for motion of a subject during an MRI scan of the subject. k-space data may be received from the MRI scan of the subject. Motion information may be received for the subject. Based on the received motion information, a translational motion of the subject may be determined between a first point in time and a second point in time. A search space for motion correction may be reduced using the determined change and an error margin of the capturing technique. A motion-compensated, graphical image of the subject may be generated using the reduced search space.

Abstract: Systems, methods and articles of manufacture are disclosed for capturing motion information in a magnetic resonance imaging (MRI) environment. A light sink in the MRI environment may detect light emitted from a plurality of light sources. Each of the plurality of light sources may emit light of a different frequency. Further, each of the plurality of light sources may be located at a different spatial position in the MRI environment. The detected light may be analyzed. A change in spatial position of the light sink may be computed based on the analysis.

Abstract: A method for magnetic resonance elastography (“MRE”) is described, in which an MRE inversion that accounts for waves propagating in a finite, bounded media is employed. A vibratory motion is induced in a subject and MRE is performed to measure one or more components of the resulting displacement produced in the subject. This displacement data is subsequently filtered to provide a more accurate and computationally efficient method of inversion. Wave equations based on the geometry of the bounded media are then utilized to calculate the material properties of the subject. Such a method allows for the performance of MRE on tissues such as the heart, eye, bladder, and prostate with more accurate results.

Abstract: A method for image reconstruction that utilizes the benefits of compressed sensing (“CS”) while incorporating a priori knowledge of object spatial support into the image reconstruction is provided. Image data is acquired from a subject, for example, with a medical imaging system, such as a magnetic resonance imaging (“MRI”) system or a computed tomography (“CT”) system. An estimate of the spatial support of the subject is produced, for example, using a low resolution image of the subject, or an image reconstructed from undersampled image data in a traditional sense. An estimate image of the subject is also produced by using traditional image reconstruction methods on the acquired image data. An image of the subject is then reconstructed using the produced estimate image and produced spatial support estimate. This method allows for the reconstruction of quality images from undersampled image data in a computationally efficient manner.

Abstract: The shear stiffness of a subject's spleen is measured using elastography techniques such as ultrasound elastography or a magnetic resonance elastography (MRE) acquisition with an MRI system. A relationship between splenic shear stiffness and portal venous blood pressure is modeled and is used to calculate portal venous blood pressure non-invasively from the measured splenic shear stiffness.

Abstract: This document provides materials and methods related to tissue scaffolds for use in replacing or augmenting various tissues in the body. For example, flexible tissue scaffolds with controlled pore geometry and methods of enhancing solute transport using rhythmic compression (e.g., 1.

Abstract: A method for image reconstruction that utilizes a generalization of compressed sensing is provided. More particularly, a method for homotopic l0 minimization is provided, in which a series of subproblems that asymptotically approach a solution to the l0 minimization are iteratively solved. These subproblems include utilizing concave metric prior functionals in the traditional compressed sensing framework. Substantially undersampled image data is acquired from a subject, for example, with a medical imaging system, such as a magnetic resonance imaging (“MRI”) system or a computed tomography (“CT”) system. Using the provided method, undersampling on the order of around 96 percent can be achieved while still producing clinically acceptable images.

Abstract: A method for displaying colonography images includes presenting a series of axial images of the colon at sequential locations along the colon centerline. Each image is generally centered on the centerline and presents a field of view parallel to the axial plane.

Abstract: A method for displaying colonography images includes presenting a series of oblique images of the colon at sequential locations along the colon centerline. Each image is generally centered on the centerline, presents a field of view generally perpendicular to the centerline, and is oriented with the bottom of the colon down.

Abstract: An improved method for processing image voxel data representative of 3-dimensional images of a colon to remove the effects of tagged stool. The method uses parabolic curve intensity-gradient models at a transition between two material types as a function of the fraction of the two materials for each of a plurality of two-material type classes, including a gas-tissue transition model, a gas-stool transition model and a stool-tissue transition model. The voxels are classified into one of a plurality of substance classes including tagged stool, gas, tissue and unknown classes. The unknown class voxels are processed to classify the unknown class voxels into one of the two-material type classes. The two-material type class voxels are processed to determine the fractions of materials in each voxel. The intensity of the two-material type class voxels is then adjusted as a function of the fraction of the materials in the voxels.

Abstract: Magnetic resonance images reconstructed from a radial/projection acquisition are corrected for motion corruption caused by in-plane translational and in-plane rotational motion of an imaged subject using only the projection data itself. The method is based on the consistency properties of the 0th, 1st, and 2nd order moments of the spatial domain projections. In-plane translational motion is corrected by shifting/aligning the spatial projections according to the center of mass of each projection, which is calculated using the 0th and 1st moments. In-plane rotational motion is accounted for by determining the rotational motion time record using the 2nd moment information. The determination of the rotational motion time record using the 2nd moments is made possible by acquiring the successive MR projections at a view angle spacing that is substantially 45° and thus achieves sufficient linear independence.

Abstract: A method for processing CT colonography input image voxel data representative of 3-dimensional images of a colon having gas and stool tagged with stool tagging agent, to remove the stool from the images. The input image voxel data is generated by an imaging instrument having a characteristic point spread function representative of instrument blurring. The point spread function of the instrument can be empirically determined, and the image data processed as a function of the point spread function to accurately identify and remove the tagged stool. In one embodiment of the invention, portions of the image data representative of the tagged stool and colon tissue are dilated as a function of the point spread function.

Abstract: A series of fMRI image frames are acquired along with interleaved navigator signals. The navigator signals are acquired while three orthogonal readout gradients are applied such that a spherical surface is sampled in k-space. The navigator signals are analyzed to measure subject rotational and translational motion during the scan.

Abstract: Magnetic resonance images reconstructed from a radial/projection acquisition are corrected for motion corruption caused by in-plane translational and in-plane rotational motion of an imaged subject using only the projection data itself. The method is based on the consistency properties of the 0th, 1st, and 2nd order moments of the spatial domain projections. In-plane translational motion is corrected by shifting/aligning the spatial projections according to the center of mass of each projection, which is calculated using the 0th and 1st moments. In-plane rotational motion is accounted for by determining the rotational motion time record using the 2nd moment information. The determination of the rotational motion time record using the 2nd moments is made possible by acquiring the successive MR projections at a view angle spacing that is substantially 45° and thus achieves sufficient linear independence.

Abstract: An MRA image is corrected for motion artifacts using an iterative, autocorrection process in which corrections are tried and the quality of the resulting reconstructed image is measured. Corrections are made to the acquired three-dimensional data while the metric which measures image quality is applied to a two-dimensional projection image.

Abstract: Two magnetic resonance frequency domain data sets are acquired with the phase and frequency encoding gradient axes swapped. A k-space phase difference data set is computed from the two acquisitions and corrections for interview in-plane, rigid body translational motion are calculated from the phase difference information and a large set of simultaneous linear equations. The two acquired data sets are corrected with phase changes to compensate for the subject motion and then combined to form a single image.

Abstract: A series of fMRI image frames are acquired along with interleaved navigator signals. The navigator signals are acquired while three orthogonal readout gradients are applied such that a spherical surface is sampled in k-space. The navigator signals are analyzed to measure subject rotational and translational motion during the scan.

Abstract: A series of MR examinations of a patient are performed and the acquired images are aligned with each other so that small anatomic changes can be detected when images are compared. Alignment is achieved by acquiring navigator signals during each examination which are analyzed to measure patient misalignment from one examination to the next. The rotational and translational misalignment information is used to either prospectively or retrospectively align the MR images.