Hitachi Medical Corporation

Hitachi, Ltd.

Shigenobu Yanaka

Hideki Kohno

Kensuke Sekihara

Hidemi Shiono

Isao Horiba

Hideaki Koizumi

Koichi Sano

Akira Maeda

Tetsuo Yokoyama

Chitose Nakaya

Teruichi Tomura

Shinji Yamamoto

Takayuki Hayakawa

Kouichi Koike

Takaji Suzuki

Yasuo Kuwabara

A method of MR dynamic imaging comprises the steps of uniformly dividing one scan which is a minimum measurement unit in generating one image data into a plurality of cycles, sequentially extracting one-scan data which are staggered by a predetermined number of cycles, from a series of data derived by repeating the scan a plurality of times in such a manner that the measurement data in each cycle includes high frequency component and low frequency component of the image, and generating image data from the extracted data.

Method of magnetic resonance dynamic imaging

A radiation-image photographing apparatus comprises a radiation source, a radiation detector disposed in opposition to the radiation source for detecting radiation through an object to be examined and to generate an electrical signal proportional to the amount of incident radiation, a scanning device for changing the relative, positional relationship between the radiation source and the radiation detector, an analog-to-digital converter for converting the output signal from the radiation detector to a digital quantity, a memory for storing the digital signal, an arithmetic unit, and a display unit. A plurality of measurements of a two-dimensional radiation absorption distribution of the object disposed between the radiation source and the radiation detector is obtained while the relative positional relationship between the radiation source and the radiation detector is being changed, and a linear arithmetic operation is performed on the plurality of image measurements, or a set of data passing a point within the object to be photographed, thereby displaying a cross-sectional image on a given cross-section approximately parallel to the radiation detector plane within the object to be examined.

Radiation image photographing apparatus

In the X-ray CT system, the X-ray detectors vary in output characteristics such as linearity, directivity and radiation quality from one detector to another. To make compensations for such irregularities, a plurality of phantoms of different absorption is prepared in the CT system according to the present invention. Namely, this plurality of phantoms is set one by one in the measuring space in the same manner as in the examination of an examinee or subject to be examined; the coefficient of X-ray absorption is determined for each of these phantoms. Further, theoretical values of absorption for each phantom are compared to the actual absorption measurements on each phantom to provide an absorption error value for each detector at differing absorption levels. The actual subject absorption value for each detector is used to pick the two error values closest to the actual value. The two error values are interpolated or extrapolated to find an error value for correcting the actual absorption value. The above method steps are advantageously implemented by one or more digital computers. The corrected subject absorption values are provided to a conventional image reconstruction device to provide the desired X-ray video image.

Method and apparatus for examining a subject

A tomographic imaging system is disclosed in which the quantity of absorption or transmittance of a transmissive radiation by or through a certain tomographic cross-section of an object under consideration is detected and the distribution of radiation absorption or transmittance in the cross-section is reconstructed through a convolution operation. A weighting function used in the convolution operation is prepared with a predetermined one of its positive orders the value of which is an integration of the weighting function from the predetermined positive order to positive infinity and a predetermined one of its negative orders the value of which is in integration of the weighting function from the predetermined negative order to negative infinity.

Tomographic imaging system

Growing community of inventors

Kashiwa, Japan

Shigenobu Yanaka