159 results about "Tomographic reconstruction" patented technology

A dynamic SPECT camera is provided, comprising, a plurality of single-pixel detectors, a timing mechanism, in communication with each single-pixel detector, configured for enabling time-binning of the radioactive emissions impinging upon each single-pixel detector to time periods not greater than substantially 30 seconds, and a position-tracker, configured for providing information on the position and orientation of each detecting unit, with respect to the overall structure, substantially at all times, during the individual motion, the dynamic SPECT camera being configured for acquiring a tomographic reconstruction image of a region of interest of about 15×15×15 cubic centimeters, during an acquisition time of 30 seconds, at a spatial resolution of at least 10×10×10 cubic millimeter. The dynamic camera is configured for very short damping time, and may further acquire images in a stationary mode, with no motion. It is further configured for time binning at dynamically varying time-bin lengths, dynamically determining a spectral energy bin for each detecting unit, and employing an anatomic construction of voxels in the imaging and reconstruction.

A tomographic reconstruction method and system incorporating Bayesian estimation techniques to inspect and classify regions of imaged objects, especially objects of the type typically found in linear, areal, or 3-dimensional arrays. The method and system requires a highly constrained model M that incorporates prior information about the object or objects to be imaged, a set of prior probabilities P(M) of possible instances of the object; a forward map that calculates the probability density P(D|M), and a set of projections D of the object. Using Bayesian estimation, the posterior probability p(M|D) is calculated and an estimated model MEST of the imaged object is generated. Classification of the imaged object into one of a plurality of classifications may be performed based on the estimated model MEST, the posterior probability p(M|D) or MAP function, or calculated expectation values of features of interest of the object.

A touch-sensitive apparatus comprises a panel configured to conduct signals from a plurality of peripheral incoupling points to a plurality of peripheral outcoupling points. Actual detection lines are defined between pairs of incoupling and outcoupling points to extend across a surface portion of the panel. The signals may be in the form of light, and objects touching the surface portion may affect the light via frustrated total internal reflection (FTIR). A signal generator is coupled to the incoupling points to generate the signals, and a signal detector is coupled to the outcoupling points to generate an output signal. A data processor operates on the output signal to enable identification of touching objects. The output signal is processed (40) to generate a set of data samples, which are indicative of detected energy for at least a subset of the actual detection lines. The set of data samples is processed (42) to generate a set of matched samples, which are indicative of estimated detected energy for fictitious detection lines that have a location on the surface portion that matches a standard geometry for tomographic reconstruction. The set of matched samples is processed (44, 46) by tomographic reconstruction to generate data indicative of a distribution of an energy-related parameter within at least part of the surface portion.

A touch-sensitive apparatus comprises a panel for conducting signals from incoupling points to outcoupling points. Detection lines are defined between pairs of incoupling and outcoupling points. A signal generator is coupled to the incoupling points to generate the signals. A data processor processes the output signal to generate a set of data samples, which are non-uniformly arranged in a two-dimensional sample space. Each data sample is indicative of detected energy on a detection line and is defined by a signal value and first and second dimension values defining the location of the detection line on the surface portion. Adjustment factors are obtained for the data samples, each adjustment factor being representative of the local density of data samples in the sample space. The data samples are processed by tomographic reconstruction, while applying the adjustment factors, to generate a reconstructed distribution of an energy-related parameter within the surface portion.

Several related inventions for estimating scattered radiation in radiographic projections are disclosed. Several of the inventions use scatter kernels of various forms, including symmetric and asymmetric forms. The inventions may be used alone or in various combinations with one another. The resulting estimates of scattered radiation may be used to correct the projections, which can improve the results of tomographic reconstructions. Still other inventions of the present application generate estimates of scattered radiation from shaded or partially shaded regions of a radiographic projection, which may be used to correct the projections or used to adjust the estimates of scattered radiation generated according to inventions of the present application that employ kernels.

The present invention is a tomographic reconstruction algorithm, which is highly effective improving image quality and accuracy by reducing or eliminating artifacts within images produced by limited data tomography. Using algebraic reconstruction techniques (ART), depending on whether or not an object has higher or lower densities, a current threshold value is set to either a high or low threshold parameter and then decreased or increased, respectively, to reduce or eliminate the artifacts in a reconstructed image.