165 results about "Conical beam" patented technology

An X-ray CT system is equipped with a gantry, couch and control cabinet and configured to scan a cone-beam X-ray toward an object along a given orbit to acquire cone-beam data in which a three-dimensional distribution of an X-ray absorption coefficient within the object is reflected. The control cabinet decides a degree of reliability for the cone-beam data according to an acquisition time of the cone-beam data, and then decides a weight for three-dimensional Radon data from the cone-beam data on the basis of the degree of reliability. Using this weight, the control cabinet reconstructs the three-dimensional Radon data based on a three-dimensional reconstruction algorithm. Thus, when the three-dimensional reconstruction algorithm for cone-beam CT is applied to medical CT, artifacts attributable to object's motion can be suppressed and temporal resolution can be improved.

A CT scanning system including a gantry operable to rotate about a rotation axis, and a plurality of X-ray imagers mounted on the gantry, each X-ray imager including a radiation source and a detector, wherein the radiation source is operative to emit a radiation beam (e.g., a cone beam) and the detector is positioned to receive the radiation beam so as to acquire partial projections set of an object through which the beams pass, wherein a union of the partial projections sets forms a projection set sufficient for CT reconstruction of the object.

A method and apparatus for imaging a body by exposing the body to radiation transmitted through the body via successive angular portions from a radiation source on one side of the body to a radiation detector in alignment with the radiation source on the opposite side of the body; the radiation detector including a two-dimensional matrix of detector elements producing electrical outputs corresponding to the magnitudes of the radiation received by each detector element; the radiation source producing a conical beam sufficiently large such that each exposure covers all the detector elements in the two-dimensional array after traversing the body. Also described are a method and apparatus for producing angiographical images having an enhanced contrast-to-noise ratio (CNR) by subtracting, from each contrast image produced after injecting a contrast material, a masking image produced before injecting the contrast material, starting with the masking image determined to have a minimum change over its immediately preceding masking image in the respective sequence.

An image reconstruction method for cone beam x-ray attenuation data acquired over a super-short-scan, short-scan or full-scan includes backproejcting over three adjacent segments of the arc traversed by the x-ray source. Each backprojection consists of a weighted combination of 1D Hilbert filtering of the modified cone-beam data along both horizontal and non-horizontal directions.

Apparatus for CT cone beam scanning, comprising:a table for holding a subject;a gantry;a first detector array, having a given number of rows of detector elements spaced along an rotation axis of the gantry, mounted on the gantry;a first plurality of x-ray sources mounted on the gantry for rotation about the patient table on a rotation axis, the number of rows being at least twice the number of sources; anda controller that acquires data responsive to radiation from the sources from the detector array attenuated by at least part of the common volume of the subject irradiated by the plurality of radiation sources.

A 3D metal artifacts correction technique corrects the streaking artifacts generated by titanium implants or other similar objects. A cone-beam computed tomography system is utilized to provide 3D images. A priori information (such as the shape information and the CT value) of high density sub-objects is acquired and used for later artifacts correction. An optimization process with iterations is applied to minimize the error and result in accurate reconstruction images of the object.