Kabushiki Kaisha Toshiba

Toshiba Medical Systems Corporation

Toshiba Corporation

Katsuyuki Taguchi

Hiroshi Aradate

Yasuo Saito

Michael D Silver

Ilmar A Hein

Tatsuro Suzuki

Aleksandr Zamyatin

Kyojiro Nambu

Hiroaki Miyazaki

Tadaharu Kobayashi

Be-Shan Chiang

Takehiro Ema

Satoru Oishi

Kazuyuki Ihira

Koichi Muraki

Shinich Yamada

Aleksandr A Zamyatin

A method of removing an imaging artifact in a medical image, including obtaining a first plurality of images, the first plurality of images collectively defining a first image volume; filtering the first plurality of images to create a second plurality of images, each image in the second plurality of images comprising an average of at least two images in the first plurality of images; selecting a first image from the first plurality of images; adding a lost noise image to a second image in the second plurality of images to create a noise restored image, the second image in the second plurality of images corresponding to the first image in the first plurality of images; determining a gradient image based on pixel values in the second plurality of images, the gradient image comprising a gradient value at each pixel location in the second image; and combining, based on the determined gradient image, the first image and the noise restored image to obtain a corrected image that does not contain the imaging artifact.

Method for helical windmill artifact reduction with noise restoration for helical multislice CT

A method of determining an image data value at a point of reconstruction in a computed tomography (CT) image of a scanned object, including obtaining projection data of the scanned object, filtering the obtained projection data with a one-dimensional ramp filter to generate ramp-filtered data, and applying a backprojection operator with inverse distance weighting to the ramp-filtered data to generate the image data value at the point of reconstruction in the CT image.

Image reconstruction method using Hilbert transform

A computed tomography apparatus, including: an X-ray helical scanning device including an X-ray generator and an X-ray detector arranged in a gantry, the helical scanning device configured to provide a continuous scan and to obtain projection data of a scanned object arranged on a platform; and control unit configured to control at least one of the X-ray helical scanning device and the platform so as to generate the continuous scan with a helical pitch that is based on a height of a detector row of the X-ray detector projected onto an iso-center of the gantry.

Subtle dynamic helical scan for uniform z-resolution and noise

A method, system, and computer program product for compensating for the unavailability of projection data of a scanned object at a selected point, the selected point located outside a detection range of a detector. The method include the steps of obtaining projection data of the scanned object, and compensating for the unavailability of the projection data at the selected point based on the obtained projection data and coordinates of the selected point relative to the detector. The compensating step includes determining at least one complementary projection angle and coordinates of at least one complementary point based on a source projection angle and the coordinates of the selected point relative to the detector, and estimating the projection data value at the selected point based on the acquired projection data, the at least one complementary projection angle, and the coordinates of the at least one complementary point.

Method for restoring truncated helical cone-beam computed tomography data

An X-ray computed tomography apparatus includes a helical scanning device configured to collect projection data while at least one of a gantry and a couch moves along a body axial direction of an object on the couch when at least one of the gantry and the couch is tilted, the helical scanning device including an X-ray source configured to generate X-rays, and a detector disposed opposite the X-ray source and having detector elements arranged in a plurality of rows along the body axial direction, and a reconstructing device configured to reconstruct an image based on the projection data using cone-beam Feldkamp reconstruction.

Tilted gantry helical cone-beam Feldkamp reconstruction for multislice CT

A method for obtaining data from CT scans, including obtaining projection data from at least one detector row in a CT system; applying a weighting function including cone-angle dependent weight to projection data; filtering weighted data; and backprojecting weighted data while accounting for cone-angle. The method finds application to an X-ray CT apparatus, including a helical scanning device configured to collect projection data while at least one of a gantry and a couch moves along an axial direction, the helical scanning device including an X-ray source to generate X-rays, and a detector having detector elements arranged in rows along the axial direction to produce projection data; and a processor, which includes a weighting device to apply a weighting function including cone-angle dependent weight to projection data, thereby obtaining weighted data, a filtering device to filter weighted data, and a backprojecting device to backproject weighted data while accounting for cone-angle.

Cone-beam reconstruction apparatus and computed tomography apparatus

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.

Cone beam type of X-ray CT system for three-dimensional reconstruction

A method and system for reconstructing an x-ray image from a partial orbit through the use of a &ldquo;virtual&rdquo; fan angle. The virtual fan angle is determined based upon the range of angular positions spanned by a source in a CT instrument or a selected smaller angle. Exposure data is obtained and he virtual fan angle is used to weight the exposure data. Image reconstruction can then proceed using the weighted exposure data. The described methods and system also function for data collected over a complete orbit.

Method and system for reconstructing computed tomography images using redundant data

An X-ray computerized tomographic apparatus includes an X-ray tube device configured to irradiate an object to be examined with a pyramidal X-ray beam, a detector which has a plurality of detecting elements arrayed in a slice direction in which X-rays transmitted through the object are detected, a data extending unit which creates virtual data corresponding to an extension region located outside a region in which the detecting elements are arranged in the slice direction on the basis of real data detected by the detecting element, and a reconstructing unit which reconstructs image data on the basis of the real data and virtual data.

X-ray computerized tomographic apparatus

A method, system, and computer-readable medium that can resolve continuous and/or relatively rapid changes with time of a volume V without deterioration in image quality. In one embodiment of this invention, a subset of the projection data collected along a continuous circular orbit is combined with projection data collected along a different orbit to reconstruct the volume V substantially as it was when the subset of the projection data was collected. In one embodiment, the different orbit is a linear or a helical orbit. Further, staggered subsets of the projection data collected along a continuous circular orbit can also be used, as can further projection data collected along a linear orbit to resolve continuous and/or relatively rapid changes of a volume V.

Reconstruction and scan of 4D-CT

Method and system for computed tomography. Data is collected by irradiating a subject with x-rays. The data is interpolated and then weighted based upon the data collection time. The interpolated and weighted data is then used to reconstruct the image using fan beam reconstruction. The weighting function may by shifted in time. Signals may be obtained from the subject and used to control exposure, reduce the dose and provide automatic volumetric cardiac reconstruction. The method and system can increase the temporal and spatial resolution, and reconstruct images at different timing.

Computed tomography system and method

An X-ray CT apparatus includes an X-ray source for generating X-rays, a detector having detector elements laid out in a plurality of rows in a body axial direction of an object on a couch for detecting X-rays transmitted through the object, and a helical data collector that collects helical data while at least one of a gantry and the couch is moved by a moving device along a body axial direction of the object on the couch in a state that at least one of the gantry and the couch is tilted. A data processor is further provided that reconstructs an image by interpolating the helical data collected and converting it into parallel beam data that is tilt corrected.

Multi-slice X-ray computed tomography apparatus

An X-ray CT scanner for producing a CT image of a subject by scanning an X-ray fan beam radiated an X-ray source through the subject in a predetermined slice-thickness direction. The scanner comprises a main detector detecting the X-ray beam to produce an X-ray transmission data of a subject and to a plurality of slices in agreement with unequal segment pitches. The detector comprises a two-dimensional array consisting of a plurality of X-ray detecting elements receiving the X-ray beam and being disposed in the slice-thickness direction as a row line and a channel direction as a column line. The X-ray detection sensitivity distributions of all the segments formed by the detecting elements disposed in predetermined element pitches in the slice-thickness direction are adjusted to be uniform or approximately uniform by controlling various members, devices, or factors which are all controllable for X-ray detection sensitivity, thereby enabling the X-ray transmission data of unequal slice thicknesses to be adjusted in sensitivity slice by slice in the detector. The scanner further comprises a switch group selecting and combining the sensitivity-adjusted X-ray transmission data of the plurality of slices, the selected and combined X-ray transmission data being provided to selected ones of a data acquiring elements of a data acquisition system.

X-ray CT scanner using X-ray detector acquiring multi-slice data of unequal slice pitches

An X-ray tomosynthesis system as an X-ray diagnostic system is provided. The system comprises an X-ray generator irradiating an X-ray toward a subject, and a planar-type X-ray detector detecting the X-ray passing through the subject and outputting two dimensional imaging signals based on the detected X-ray. The system comprises a supporting/moving mechanism supporting at least one of the X-ray generator and the X-ray detector so that the at least one is moved relatively to the subject. The system also comprises an element setting a ROI position of the subject, an element for obtaining a plurality of three dimensional coordinates of pixels included in the ROI, a calculating element obtaining two dimensional coordinates of data in the two dimensional imaging signals for each of the two dimensional imaging signals detected by the X-ray detector, the data being necessary for obtaining pixel values of the three dimensional coordinates; and an element for obtaining the pixel value of each of the three dimensional coordinates by extracting the corresponding data of the two dimensional coordinates from the detected two dimensional imaging signals and adding the extracting data.

Growing community of inventors

Buffalo Grove, IL, United States of America

Katsuyuki Taguchi