Hitachi, Ltd.

Hitachi Medical Corporation

Yasutaka Konno

Fumito Watanabe

Shinichi Kojima

Yushi Tsubota

Hironori Ueki

Keisuke Yamakawa

Isao Takahashi

Kazuma Yokoi

Shinji Kurokawa

Atsuro Suzuki

Takashi Ishikawa

Osamu Miyazaki

Yuichiro Ueno

Eiji Moro

Fuyuhiko Teramoto

An X-ray CT data processing device is provided which when multi-energy photography is performed with an energy-separation type detector, and a subject is separated into a plurality of standard materials to create an image, estimates the appropriateness of posited standard materials, and in order to determine appropriate standard materials with satisfactory accuracy, processes CT data respectively acquired in a plurality of detection energy ranges to create a reconstructed image separated into predetermined standard materials. The X-ray CT data processing device is equipped with a standard material data calculating part which calculates energy-independent physical quantities for a plurality of standard materials respectively using different combinations of a plurality of the CT data, and creates a plurality of standard material data for the same standard material, and an appropriateness determination index creating part which creates an index for determining the appropriateness of the standard material, based on the plurality of standard material data calculated by the standard material data calculating part.

X-ray CT data processing device and X-ray CT device comprising same

This is directed to calculating physical amounts of a plurality of types of basis materials without having to increase a calculation time. An image processing device is provided which includes a first basis material transformation unit that calculates each of physical amounts of two or more basis materials included in a first basis material group based on two or more types of projection data different in energy distribution, an image generation unit that generates a plurality of images, each of which is at least one of a projection image and a reconstructed image of an object, from physical amounts of two or more basis materials included in the first basis material group, and a second basis material transformation unit that calculates a physical amount of a basis material included in a second basis material group which is different from the first basis material group based on the plurality of images.

Image processing device, X-ray CT device, and image processing method

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

There is disclosed an X-ray detector that includes a detection section, an addition rate determination section, an addition section, and a position information storage section in order to enhance the accuracy of interpolation of an output signal from a defective element and suppress artifacts with ease without increasing, for example, the length of processing time, the number of processing circuits, and the amount of interpolation data. The detection section includes a plurality of arrays of detection element groups that are each formed of a plurality of detection elements in correspondence with one pixel. The addition rate determination section determines addition rates for output signals of the detection elements. The addition section calculates the signal value of each pixel of a projection image by adding the output signals of the detection elements belonging to the detection element groups in accordance with the addition rates. The position information storage section stores pixel position information and defective element position information. The pixel position information indicates the positional relationship between the pixel and the detection elements. The defective element position information indicates the position of a defective element. Based on the pixel position information and the defective element position information, the addition rate determination section determines the addition rate for the output signal of the defective element and the addition rate for the output signal of a diagonal detection element positioned symmetrically with respect to the defective element in such a manner that the addition rates are equal and lower than the addition rates for the other detection elements and that the addition rates for the other detection elements are substantially equal.

X-ray detector, X-ray CT device, X-ray detection method, and X-ray detection program

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

In an X-ray scanning apparatus including a photon counting type X-ray detection element, in order to perform counted number correction specialized for pile-up with high accuracy, the X-ray scanning apparatus includes an X-ray detector in which a plurality of photon counting type X-ray detection elements are disposed, each of the X-ray detection elements detecting an incident X-ray photon, classifying energy of the X-ray photon into two or more energy ranges, and counting the X-ray photon, and a correction unit that corrects the counted number in the X-ray detection element, in which the correction unit includes a counting error amount determination part that determines a counting error amount in a counted number due to pile-up according to a pile-up occurrence probability in two or more X-ray photons.

X-ray imaging 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

In an X-ray scanning apparatus mounted with a photon counting type radiation detector, a data processing device of the X-ray scanning apparatus includes a correction unit that corrects a digital output value in each of the plurality of energy ranges with respect to each X-ray detection element in order to obtain an accurate projection image by correcting a counting error of the number of X-ray photons in each energy range. The correction unit includes an inflow amount calculation portion that calculates a digital amount corresponding to X-ray photons which flow from a certain X-ray detection element to another X-ray detection element, and an energy shift inflow amount/outflow amount calculation portion that calculates a digital amount corresponding to X-ray photons which flow into a high energy range due to energy shift in a single X-ray detection element, and performs correction by using the digital amounts calculated by the calculation portions.

X-ray scanning apparatus

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

An image processing device or radiation imaging device for generating an image using output data from a detector for detecting a radiation transmitted through an object to be examined, wherein artifacts caused by a gap between an estimated output value and the true output value are reduced when estimating an output value of a defective element of the detector. Correction is performed not only for the output of the defective element but for the output of the surrounding normal elements used for the defective element correction by a blurring process. Additionally, whether or not to perform the blurring process for the surrounding normal elements and the degree of the blurring process are adjusted according to the device conditions, scanning conditions, and the like.

Image processing device, radiation imaging device, and image processing 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

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.

Growing community of inventors

Tokyo, Japan

Yasutaka Konno