Hitachi, Ltd.

Hitachi Medical Corporation

Fujifilm Healthcare Corporation

Fumito Watanabe

Yasutaka Konno

Shinichi Kojima

Yushi Tsubota

Hironori Ueki

Isao Takahashi

Keisuke Yamakawa

Kazuma Yokoi

Takafumi Ishitsu

Shinji Kurokawa

Masafumi Onouchi

Fuyuhiko Teramoto

Atsuro Suzuki

Yuichiro Ueno

Eiji Moro

Taiga Gotou

A material decomposition apparatus for performing decomposition of a material in an object. The apparatus includes a data storage section for storing correction data preliminarily generated by decomposing one of three or more materials into the other two materials, a data input section to which radiation data of the object is inputted, the radiation data being divided into a plurality of energy levels, and a decomposition processing section for repeatedly performing two-material decomposition for decomposition of the other two materials of the three or more materials using the radiation data at different energy levels and the correction data to perform decomposition of the inside of the object into the three or more materials.

Material decomposition apparatus, PCCT apparatus, and material decomposition method

The present invention provides a radiation imaging apparatus capable of maintaining the quality of an image obtained even when a dose incident on a radiation detector changes suddenly. The present invention is a radiation imaging apparatus including a radiation source, a radiation detector to detect radiation emitted from the radiation source, and a cooling unit to cool the radiation detector; and is characterized in that the radiation detector has a counting circuit to output a number of photons in radiation counted per unit time as a photon counting rate, and the cooling unit controls a coolability of the radiation detector in response to the photon counting rate.

Radiation imaging apparatus

To provide a radiation imaging system which is adapted to downsize a photon counting radiation detector including a semiconductor layer for detecting photons of radiation and a collimator for suppressing incidence of scattered rays, and which ensures high voltage resistance. The radiation imaging system includes: a radiation source; a radiation detector; and a support portion for supporting the radiation source and the radiation detector in opposed relation. The system has a structure wherein the radiation detector includes a plurality of detecting element modules arranged in an arcuate form. The detecting element module includes a base fixed to the support portion; a semiconductor layer; a high-voltage wire for supplying high voltage to the semiconductor layer; a collimator for suppressing scattered rays, and a supporting column disposed at place within a predetermined distance from the semiconductor layer.

Radiation imaging system

X-ray photons are counted as to each of energy bands (bins) to which optimum energy ranges are provided, and an image with reduced noise is displayed in a short time. An energy range of at least one of multiple energy bands in an X-ray detector is adjusted, on the basis of a distribution of degrees of X-ray attenuation at respective energy levels, the distribution of degrees of X-ray attenuation being measured in advance with respect to a predetermined direction of a subject. By using the X-ray detector with the energy bands after the adjustment, photon-counting CT imaging is performed.

Photon-counting CT device, and CT imaging method using photon counting

The present invention is directed to make a photon-counting CT apparatus capable of more accurate data acquisition. Such apparatus is provided with a reference detection unit and a time measuring instrument to measure temporal fluctuations in a rotational direction of an X-ray irradiation unit. The apparatus corrects temporal fluctuations in the rotational direction involved in data measured by the reference detection unit, using time measurement data which is output by the time measuring instrument. Using corrected measurement data measured by the reference detection unit, the apparatus makes corrections of fluctuations pertaining to the X-ray tube of the X-ray irradiation unit and pile-up. Data corrections with high accuracy are thus enabled.

Photon-counting CT apparatus

A flat pixel () is a single unit composing a radiation detector and is configured so as to be divided into at least four subpixels () such that even if a prescribed number of subpixels () are removed from each pixel () in order of largest effective area, the centroid () of the effective area of the entirety of the remaining subpixels () is positioned within a similar-shape region () having the same centroid () as the pixel () and having sides of lengths that are half those of the pixel ().

Radiation detector, radiation imaging device, computer tomography device, and radiation detection method

A change of X-ray radiation quality due to a material existing between an X-ray source and a detection element is estimated and corrected. Accordingly, deterioration of material discrimination ability in a dual energy imaging method can be prevented. An X-ray imaging apparatus is provided with an inherent filtration calculator configured to use measured data obtained by imaging air at two or more types of different tube voltages to calculate a deviation from a reference radiation quality, as a transmission length (inherent filtration) of a predetermined reference material. A reference-material transmission-length conversion is applied to the measured data according to the dual energy imaging method, thereby calculating the reference material transmission length (inherent filtration). When a subject is imaged, the dual energy imaging is performed by adding the inherent filtration calculated as to each detection element, and this produces an image with the change of radiation quality having been corrected.

X-ray image pickup apparatus, X-ray image pickup method, and X-ray image pickup apparatus monitoring method

Provided is a technique in an X-ray imaging apparatus for implementing data interpolation approximating an ideal point response trajectory interpolation, along with reducing calculation load. A method is provided to perform interpolation at high speed, in a direction along the point response trajectory. Sinograms are interpolated in advance from measured data, as to representative angles (e.g., 0&#xb0;, &#xb1;30&#xb0;, &#xb1;60&#xb0;, and 90&#xb0;) only. When a pixel targeted for back projection is determined at the time of reconstruction, a slope of the point response trajectory is determined as to each view. According to the slope of the trajectory, each representative sinogram is added with weight, whereby interpolation data in association with any angle can be obtained.

X-ray image pickup device and image reconstruction method

The present invention is capable of distinguishing four types or more of substances such as air, water (soft tissues), contrast medium, and bones (calcification) to diagnose progress of atherosclerotic sites using dual energy imaging. A subject is imaged with two types of different tube voltages and an image obtained by image reconstruction is binarized to carry out a reprojection process; thereby, the distance of penetration of air is estimated, the contribution of air in measurement projection data is determined, and the amount of reduction by the air is deducted from the projection data so as to enable distinction between four or more substances such as air, water (soft tissues), contrast medium, and bones (calcification).

X-ray CT device and processing method

In X-ray CT devices, degradation of quantitative determination ability for CT values resulting from the beam hardening (BH) effect of X-ray is prevented. X-ray absorption characteristic S obtained by simulation and a target value T thereof are saved beforehand, the simulation value S is revised by using projection data measured by maintenance measurement for obtaining basic data required for BH correction, and a BH correction coefficient is calculated by using the revised X-ray absorption characteristic S and the target value T. With a few actually measured values, BH correction accuracy can be improved, and reduction of incorrect diagnosis resulting from inhomogeneity of the CT values and improvement in the diagnostic ability based on improvement in quantitative determination ability for the CT values can be realized.

X-ray CT device, calcuration device, recording medium for X-ray CT device, and maintenance method for X-ray CT device

Difference of resolution depending on imaging position in one reconstructed image generated in the FFS method is reduced to improve measurement accuracy. The X-ray CT device interpolates missing data of the projection data obtained by the FFS method with view direction interpolation processing using real data of the projection data lining up along the angular direction of the rotational movement, and channel direction interpolation processing using real data of the projection data lining up along the channel direction, and generates a reconstructed image, in which contribution ratios of the projection data having been subjected to the view direction interpolation processing and the projection data having been subjected to the channel direction interpolation processing differ according to position of pixel in the reconstructed image.

X-ray CT device, and image reconfiguration method

An X-ray CT apparatus includes: an X-ray generating unit configured to generate an X ray; an X-ray detecting unit including a plurality of X-ray detectors, each configured to detect the X ray generated from the X-ray generating unit and transmitted through an object; and an image generating unit configured to correct and reconstruct signals acquired by the X-ray detecting unit. While crosstalk correction of a plurality of the X-ray detectors is performed at the image generating unit, correction of a locally attenuating component is previously performed and correction of a whole component of the crosstalk is performed when the image is reconstructed.

X-ray CT apparatus

In order to suppress reduction in sensitivity when acquiring high-resolution data, an X-ray CT device is provided with an X-ray source that irradiates a patient with X-rays, and an X-ray detector that detects the X-rays. The X-ray detector includes a plurality of detection elements (scintillators and photodiodes) arrayed in a first direction, and a plurality of separators that separate the detection elements arrayed in the first direction respectively from each other. The separators each have a first-direction width which is a width in the first direction, first-direction widths of some separators each arrayed every predetermined number of separators being different from first-direction widths of the other separators.

X-ray CT device

It is an object to prevent a poor X-ray CT image due to scattered X-rays. An X-ray CT scanner () uses an X-ray detector (), etc., to scan (F) an object () to obtain X-ray transmission image data, and estimate (F) an X-ray absorption coefficient distribution inside the object () based on the scanned X-ray transmission image data. Next, the X-ray CT scanner () performs a Monte Carlo simulation on a simulated object () having the X-ray absorption coefficient distribution estimated, and estimates (Fand F) a point spread function or scattered X-ray distribution derived from the object. Then, the X-ray CT scanner () corrects (Fand F), based on the point spread function or scattered X-ray distribution estimated, the X-ray transmission image data, and finally creates (Fand F) an image of the X-ray absorption coefficient distribution of the object ().

X-ray CT device and method for correcting scattered X-rays

In order to improve the tiling workability in manufacturing an X-ray detector and provide a technology for acquiring high-quality reconstruction images, when aligning a plurality of detector blocks (or detector modules) in a slice direction, a distance between adjacent X-ray detection elements between detector blocks (inter-block distance) is not matched with a distance between adjacent detector elements within a detector block (intra-block distance). Instead, between reference positions when manufacturing each detector block, output values at the positions, the number of which is the same as the number of X-ray detection elements between the reference positions and which are spaced at equal intervals, are estimated from the acquired raw data. Projection data is generated from the position and the raw data.

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Tokyo, Japan

Fumito Watanabe