摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A method for processing and displaying colonography image data. First distance tissue pixels representative of tissue within a first distance of gas pixels representative of gas are processed with a first window/level setting to generate a first setting set of image pixels. Second distance tissue pixels representative of tissue within a second distance of the gas pixels are processed with a second window/level setting to generate a second setting set of image pixels. The second distance is a distance greater than the first distance. A colonography image including both the first and second setting sets of image pixels is then displayed.
摘要:
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. In another embodiment, portions of the image data representative of the tagged stool are convolved with the point spread function to determine the fractional amount of stool present in the image portions, and the tagged stool subtracted by reducing the intensities of the associated portions of the image by an amount proportional to the fractional amount of stool present.
摘要:
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., 1.0 Hz) of tissue scaffolds are provided
摘要:
An MRI 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. Metrics based on the gradient of the reconstructed image are employed to measure image quality.