Abstract: In order to approximate the gradient magnetic field pulse waveform shape with high accuracy and improve the image quality at the time of imaging cross-section change or oblique imaging, an MRI apparatus of the present invention divides the waveform shape of the gradient magnetic field pulse into a plurality of sections, defines an approximation function for each section, and corrects the k-space coordinates at which the echo signal is arranged using the parameter of the approximation function. In addition, an optimal parameter of the approximation function of the waveform shape of the gradient magnetic field pulse is searched for using the measured signal.

Abstract: In order to obtain a highly reliable image with no image distortion or no artifacts, such as ghosting, by compensating for the distortion of an output gradient magnetic field waveform caused by various factors with high accuracy, an input gradient magnetic field waveform and an output gradient magnetic field waveform corresponding to the input gradient magnetic field waveform are calculated, a response function that is a sum of response functions of a plurality of elements affecting the output gradient magnetic field waveform is calculated using the input gradient magnetic field waveform and the output gradient magnetic field waveform, an output gradient magnetic field waveform is calculated from an input gradient magnetic field waveform of a gradient magnetic field pulse set in the imaging sequence using the response function, and various kinds of correction are performed using the calculated value of the calculated output gradient magnetic field waveform.

Abstract: Desired imaging is performed within the SAR restriction without changing the imaging conditions set in advance when SAR exceeds an upper limit. In order to do so, in imaging of an object performed by combination of a plurality of pulse sequences, a SAR graph showing a temporal change in the predicted SAR value of each pulse sequence is displayed. When the predicted SAR value of the pulse sequence is the same as or exceeds the upper SAR limit, the exchange of such pulse sequences or the insertion of a waiting time is performed.

Abstract: In multi-slice imaging of a magnetic resonance imaging apparatus based on a non-Cartesian sampling method in which an overlap portion is generated in k space, stable body movement correction is realized at high speed. In order to do so, the rotation and translation of an object is detected for each specific region (in the case of a hybrid radial method, each blade) using a most characteristic slice in the imaging region, and the detected body movement is used for body movement correction of the specific region in all slices. The slice used for correction may be determined using a mathematical analysis result, such as correlation. In addition, data collection and correction processing may be performed in parallel.

Abstract: In order to obtain a highly reliable image with no image distortion or no artifacts, such as ghosting, by compensating for the distortion of an output gradient magnetic field waveform caused by various factors with high accuracy, an input gradient magnetic field waveform and an output gradient magnetic field waveform corresponding to the input gradient magnetic field waveform are calculated, a response function that is a sum of response functions of a plurality of elements affecting the output gradient magnetic field waveform is calculated using the input gradient magnetic field waveform and the output gradient magnetic field waveform, an output gradient magnetic field waveform is calculated from an input gradient magnetic field waveform of a gradient magnetic field pulse set in the imaging sequence using the response function, and various kinds of correction are performed using the calculated value of the calculated output gradient magnetic field waveform.

Abstract: In order to approximate the gradient magnetic field pulse waveform shape with high accuracy and improve the image quality at the time of imaging cross-section change or oblique imaging, an MRI apparatus of the present invention divides the waveform shape of the gradient magnetic field pulse into a plurality of sections, defines an approximation function for each section, and corrects the k-space coordinates at which the echo signal is arranged using the parameter of the approximation function. In addition, an optimal parameter of the approximation function of the waveform shape of the gradient magnetic field pulse is searched for using the measured signal.

Abstract: In multi-slice imaging of a magnetic resonance imaging apparatus based on a non-Cartesian sampling method in which an overlap portion is generated in k space, stable body movement correction is realized at high speed. In order to do so, the rotation and translation of an object is detected for each specific region (in the case of a hybrid radial method, each blade) using a most characteristic slice in the imaging region, and the detected body movement is used for body movement correction of the specific region in all slices. The slice used for correction may be determined using a mathematical analysis result, such as correlation. In addition, data collection and correction processing may be performed in parallel.

Abstract: Desired imaging is performed within the SAR restriction without changing the imaging conditions set in advance when SAR exceeds an upper limit. In order to do so, in imaging of an object performed by combination of a plurality of pulse sequences, a SAR graph showing a temporal change in the predicted SAR value of each pulse sequence is displayed. When the predicted SAR value of the pulse sequence is the same as or exceeds the upper SAR limit, the exchange of such pulse sequences or the insertion of a waiting time is performed.

Abstract: An object of the present invention is to provide a refrigerant in which an odorant is added, the odorant being compatible with refrigerants and refrigerating device oils, and having no reactivity with refrigerating device oils and materials forming refrigerating circuits, and to provide a refrigerating device in which the refrigerant is circulated in the refrigerating circuit. A refrigerant whose main component is a hydrocarbon having 1 to 4 carbon atoms, or a flammable hydrocarbon fluoride obtained when one or more hydrogen atoms of the hydrocarbon is substituted by fluorine atoms, the refrigerant containing a tetrahydrothiophene as an odorant, and a refrigerating device in which the refrigerant is circulated are provided.

Abstract: An object of the present invention is to provide a refrigerant in which an odorant is added, the odorant being compatible with refrigerants and refrigerating device oils, and having no reactivity with refrigerating device oils and materials forming refrigerating circuits, and to provide a refrigerating device in which the refrigerant is circulated in the refrigerating circuit. A refrigerant whose main component is a hydrocarbon having 1 to 4 carbon atoms, or a flammable hydrocarbon fluoride obtained when one or more hydrogen atoms of the hydrocarbon is substituted by fluorine atoms, the refrigerant containing a tetrahydrothiophene as an odorant, and a refrigerating device in which the refrigerant is circulated are provided.

Abstract: An object of the present invention is to provide a refrigerant in which an odorant is added, the odorant being compatible with refrigerants and refrigerating device oils, and having no reactivity with refrigerating device oils and materials forming refrigerating circuits, and to provide a refrigerating device in which the refrigerant is circulated in the refrigerating circuit.

Abstract: A refrigerating device is provided whose burden on the environment is small, and in which a high amount of heat can be removed, and in which return of refrigerating device oil to a compressor is good. In the refrigerating device, carbon dioxide is circulated as a refrigerant through a refrigerating circuit in which at least a refrigerant compressor, a heat releasing device, an expansion mechanism and an evaporator are connected in an annular arrangement by refrigerant pipes. The refrigerating device oil used in the compressor has a viscosity at 40° C. of 5 to 300 cSt, a volume specific resistivity of at least 108 &OHgr;·cm, and a pour point of no higher than −30° C. when the carbon dioxide is dissolved to saturation. Organic materials which do not physically and/or chemically change due to high-temperature, high-pressure carbon dioxide are used in the refrigerating circuit. The refrigerating circuit is provided with a device for trapping moisture within the refrigerating circuit.

Abstract: An object of the present invention is to provide a refrigerant in which an odorant is added, the odorant being compatible with refrigerants and refrigerating device oils, and having no reactivity with refrigerating device oils and materials forming refrigerating circuits, and to provide a refrigerating device in which the refrigerant is circulated in the refrigerating circuit.