Abstract: Provided is a magnetic resonance imaging apparatus capable of highly precisely detecting and compensating body motions within a short processing time during radial scanning. The magnetic resonance imaging apparatus includes a control unit that applies radiofrequency magnetic fields and magnetic field gradients to a subject lying down in a static magnetic field and that detects magnetic resonance signals generated from the subject, and an arithmetic unit that handles the signals. The arithmetic unit performs subject's body motion detection in an image space, uses an image, which is reconstructed using the low-frequency portion of the k-space data of the image, as criterial data, produces templates by moving the criterial data in advance by predetermined magnitudes of rotations and predetermined magnitudes of translations, and uses the produced templates to perform the body motion detection.

Abstract: In performing the moving table imaging, an MRI apparatus and a method thereof are provided, which minimizes image degradation and reduces imaging time. When an image of a wide range of a test object is taken, the imaging is repeated while changing the gradient magnetic field intensity in a phase-encode direction, as well as changing the size of field of view FOV in the readout direction by changing the readout gradient magnetic field intensity in reading out the data, according to the phase-encode amount. In a part where the FOV is expanded, data acquisition frequency is lowered, and consequently, the total imaging time is reduced. The data sampling time may be changed along with the change of the FOV, and therefore, a process for achieving a unique matrix size in the readout direction is rendered unnecessary, and a spatial resolution can be maintained.

Abstract: The present invention provides a magnetic resonance imaging system capable of performing spectrum measurement even when a magnetic resonant frequency changes during MRS measurement. A time-varying rate of a water magnetic resonant frequency is measured in advance before the MRS measurement. The amount of change in water magnetic resonant frequency during the MRS measurement is predicted from the measured time-varying rate. With the predicted value as the reference, a transmission frequency of an RF magnetic field irradiated in a signal suppression pulse sequence, a transmission frequency of an RF magnetic field for excitation and inversion and a received frequency at the detection of a magnetic resonance signal in a sequence of the MRS measurement are respectively set. A high-precision spectrum measurement is hence enabled.

Abstract: In the continuous moving table imaging, high-speed imaging such as the echo planar method is implemented without deteriorating image quality, realizing a high-speed table movement, namely, high-speed imaging. In the magnetic resonance imaging apparatus, an imaging control means for controlling a magnetic field generation means, a transfer means, and a signal processing means executes an imaging sequence for applying multiple readout gradient magnetic fields to measure multiple nuclear magnetic resonance signals, after one-time application of an exciting RF pulse, while moving the transfer means. On this occasion, a positional deviation of the readout gradient magnetic fields given to the multiple nuclear magnetic resonance signals, caused by the movement of the transfer means, is calculated in advance as correction data, so that the measured nuclear magnetic resonance signals are corrected by the correction data.

Abstract: There is provided an MRI apparatus that is capable of imaging ON/OFF in response to a biological gating signal and changing conditions for imaging, even while the moving bed imaging is performed, and further reducing a load on a subject to be examined, which is caused by fluctuations in the bed moving velocity. A controller that controls a bed to transport the examined subject in a static magnetic field and a unit to apply an RF magnetic field and a gradient magnetic field for imaging configures settings so that the bed moving velocity is kept constant considering an entire imaging time, and further controls the magnetic applying unit for applying the RF magnetic field and the gradient magnetic field so that a moving velocity of the FOV (imaging area) in the subject coordinate system is made different from the bed moving velocity.

Abstract: The present invention provides a magnetic resonance imaging system capable of performing spectrum measurement even when a magnetic resonant frequency changes during MRS measurement. A time-varying rate of a water magnetic resonant frequency is measured in advance before the MRS measurement. The amount of change in water magnetic resonant frequency during the MRS measurement is predicted from the measured time-varying rate. With the predicted value as the reference, a transmission frequency of an RF magnetic field irradiated in a signal suppression pulse sequence, a transmission frequency of an RF magnetic field for excitation and inversion and a received frequency at the detection of a magnetic resonance signal in a sequence of the MRS measurement are respectively set. A high-precision spectrum measurement is hence enabled.

Abstract: A magnetic resonance imaging apparatus comprises static magnetic field generating means for generating a static magnetic field in an imaging space, a gradient magnetic field generating means for generating a gradient magnetic field in the imaging space, high-frequency magnetic field generating means for generating a high-frequency magnetic field so as to induce nuclear magnetic resonance in a subject placed in the imaging space, signal receiving means for detecting a nuclear magnetic resonance signal from the subject, signal processing means for reconstructing an image by using the detected nuclear magnetic resonance signal, display means for displaying the image, a table for placing the subject thereon to dispose the subject in the imaging means, and table moving means for moving the table on which the subject is placed. While moving the portions to be imaged of the subject continuously or stepwise in the imaging space and disposing the subject, a whole-body image of a large region of the subject is created.

Abstract: A control means controls an imaging means for taking an image of a test object by a magnetic resonance, the test object being placed in an imaging space, and a transfer means that moves the test object, and on the basis of a difference (moving distance) between a position of the transfer means at the time of receiving a command of pausing the imaging and a position of the transfer means at the time of resuming the imaging, the control means controls the position of the transfer means or the position for imaging at the time of resuming, in such a manner that missing of data 503 caused by the difference can be compensated. With this configuration, it is possible to provide an MRI apparatus that is provided with an imaging pause function, and even when the pause function is activated, there is data consistency between the data before the pausing and the data after the resuming, thereby obtaining a high quality image.

Abstract: An MRI apparatus suitable for realizing selective excitation utilizing multiple RF transmitting coils (parallel transmission) is provided. This MRI apparatus is provided with, as an RF receiving coil or RF transmitting coil, an RF transmitting coil 104 comprising a loop coil 210, primary differential coil 220 and secondary differential coil 230 having a common central axis 201. Upon imaging, the coils 210, 220 and 230 constituting the RF transmitting coil 104 are simultaneously driven by RF signals with the same phase, and only the differential coils 220 and 230 are driven in the second half of irradiation time with phases different by 180° from the phases for the first half.

Abstract: An MRI apparatus and method are provided which are capable of properly setting imaging position of regions of a subject on a table and moving the table to the set positions, for imaging a wide range or the entire body range of the subject.

Abstract: The magnetic resonance imaging apparatus includes a control unit for controlling a pulse sequence that applies an RF magnetic field and a magnetic field gradient to a subject placed in a static magnetic field and detects a magnetic resonance signal generated from the subject, and a calculation unit for processing the signal, and the control unit performs the process including the steps of; (1) obtaining first images at different positions in a first direction, (2) obtaining images after the first images are subjected to correction of brightness distortion, (3) obtaining images after the images as to which the brightness distortion has been corrected are further subjected to correction of positional distortion, and (4) synthesizing by a weighting calculation, overlapping areas of the images, after the positional distortion thereof has been corrected.

Abstract: A magnetic resonance imaging apparatus including signal receiving means for detecting a nuclear magnetic resonance signal from an object, signal processing means for reconstructing an image by using the detected nuclear magnetic resonance signal and display means for displaying the image, a whole image of the examiner being obtained while each imaging site of the object is continuously or stepwise moved and disposed in the imaging space, is equipped with detecting means for detecting the gradient and size of each site of the object, inputting means for inputting reference information for carrying out magnetic resonance imaging corresponding to the gradient and size of each site of the object onto an image representing the gradient and size of each site of the object which is displayed on the display means, storage means for storing the input reference information, control means for controlling the imaging operation on the basis of the reference information stored in the storage means, and combining means for

Abstract: An MRI system capable of acquiring a high-quality blood vessel image even during a measuring period other than at an injected contrast medium concentration peak by always picking up an image under optimum conditions while following up with an injected contrast medium concentration that changes every moment in the body. A flip angle is changed according to a contrast medium concentration b(t) as shown by a curve (102). During a period (Da) where a contrast medium concentration b(t) gradually increases, a flip angle (FA) increases according to a contrast medium concentration b(t); and during a period (Db) where a contrast medium concentration b(t) gradually decrease, a flip angle is gradually decreased. If a flip angle is controlled so as to follow up with a contrast medium concentration b(t) and reach an Ernst's angle at which a single intensity is at a maximum, a high-quality blood vessel image can be acquired even during a measuring period other than at an injected contrast medium concentration peak.

Abstract: In a broadband access network, calls can be kept active even when a telephone network fails. A voice gateway function captures callee telephone number information sent from a caller subscriber telephone to the telephone network and, when the telephone network fails, keeps the call active by retaining the connection between the caller and the callee. Furthermore, when the telephone network fails, the operation mode of the voice gateway and all ONTs is switched from an H.248 gateway mode to an SIP softswitch mode, allowing the voice gateway function to relay communication packets between ONTs and new call connections to be made in the broadband access network.

Abstract: A magnetic resonance imaging system is provided wherein measurement data (k space data) is extracted easily (and instantaneously) after imaging a plurality of times phases, and an image can be displayed in dynamic MRA measurement employing a contrast medium. Dynamic measurement is carried out, including extracting the time phase evaluation values (e.g. the origin data in k space) in respective time phases and then automatically extracting a data set including a time phase where the time phase evaluation value reaches a specified threshold value.

Abstract: Provided is a magnetic resonance imaging apparatus capable of highly precisely detecting and compensating body motions within a short processing time during radial scanning. The magnetic resonance imaging apparatus includes a control unit that applies radiofrequency magnetic fields and magnetic field gradients to a subject lying down in a static magnetic field and that detects magnetic resonance signals generated from the subject, and an arithmetic unit that handles the signals. The arithmetic unit performs subject's body motion detection in an image space, uses an image, which is reconstructed using the low-frequency portion of the k-space data of the image, as criterial data, produces templates by moving the criterial data in advance by predetermined magnitudes of rotations and predetermined magnitudes of translations, and uses the produced templates to perform the body motion detection.

Abstract: There is provided an MRI apparatus that is capable of imaging ON/OFF in response to a biological gating signal and changing conditions for imaging, even while the moving bed imaging is performed, and further reducing a load on a subject to be examined, which is caused by fluctuations in the bed moving velocity. A controller that controls a bed to transport the examined subject in a static magnetic field and a unit to apply an RF magnetic field and a gradient magnetic field for imaging configures settings so that the bed moving velocity is kept constant considering an entire imaging time, and further controls the magnetic applying unit for applying the RF magnetic field and the gradient magnetic field so that a moving velocity of the FOV (imaging area) in the subject coordinate system is made different from the bed moving velocity.

Abstract: In a magnetic resonance imaging apparatus, an RF pulse is applied to a subject placed in a static magnetic field, a plurality of gradient magnetic fields are applied, and induced nuclear magnetic resonance signal (echo signal) is received by means of a RF receiving coil unit composed of two or more RF receiving coils. A parallel MRI method is applied to echo signals acquired by reducing the echoes per blade of a propeller MRI method so as to remove the artifact to produce a reconstructed image. The reconstructed image is subjected to inverse Fourier transform to return it to the echo signals in a measurement space corresponding to the blade. The echo signals are girded in an arbitrarily predetermined coordinate system for image and combined. Such a processing is conducted for the echo signals of all the blades. A final image is reconstructed using the echo signals after the image creation in the coordinate system for image.

Abstract: A magnetic resonance imaging apparatus comprises static magnetic field generating means for generating a static magnetic field in an imaging space, a gradient magnetic field generating means for generating a gradient magnetic field in the imaging space, high-frequency magnetic field generating means for generating a high-frequency magnetic field so as to induce nuclear magnetic resonance in a subject placed in the imaging space, signal receiving means for detecting a nuclear magnetic resonance signal from the subject, signal processing means for reconstructing an image by using the detected nuclear magnetic resonance signal, display means for displaying the image, a table for placing the subject thereon to dispose the subject in the imaging means, and table moving means for moving the table on which the subject is placed. While moving the portions to be imaged of the subject continuously or stepwise in the imaging space and disposing the subject, a whole-body image of a large region of the subject is created.

Abstract: A magnetic resonance imaging method includes a step (1) for exciting atomic nuclei in a desired region of an object to be examined so as to cause nuclear magnetic resonance, a step (2) for detecting a nuclear magnetic resonance signal generated in the blood, and a step (3) for extracting a blood image of the object by the detected nuclear magnetic resonance signal. The desired region excited by the step (1) represents a plurality of regions arranged at a predetermined interval.