Abstract: To provide a diagnostic apparatus utilizing nuclear magnetic resonance suitable for interventional MRI which is not limited as to selection of an imaging section and an phase-encoding axis, the reception coil thereof includes three loop coils arranged so as to surround an object to be examined and to be within a plane including a line segment parallel to a static magnetic field direction, and two surface coils arranged in the vicinity of the surface of the object within a plane including a line segment perpendicular to the static magnetic field direction. In the reception coil, two or more sub-coils have nonuniform sensitivity profiles along an arbitrary axis. Therefore, the reception coil configured to have sensitivity throughout the imaging areas can be realized.

Abstract: When data of plural original images having different echo times are acquired to produce water/fat separated images by performing an processing operations in an MRI apparatus, a partial region of the original image data is specified and the specified region is subjected to the water/fat separation processing. Since noise components included in the specified region are fewer than those in the original image data, errors occurring due to noise components during unwrapping and other such processing operations can be reduced and image quality degradation be suppressed. Therefore, water/fat separated images having an excellent image quality can be produced. When echoes having different echo times are generated, rewind pulses are applied ahead of the readout gradient magnetic fields to equalize the polarities of the readout gradient magnetic fields. Consequently, influence of application of gradient magnetic fields on echo signals can be suppressed and the accuracy of water/fat separation can be improved.

Abstract: A magnetic resonance imaging apparatus is provided with a sequencer 4 for executing a rapid imaging sequence of up to 100 ms at a full scan, a parallel measurement system 101 for executing a partial encoding measurement in which the number of phase encoding operations performed for the measurement is reduced, an image processing system 102 for reconstructing images from the information obtained though the parallel measurements and composing reconstructed images of a plurality of areas to make one image, a display system 103 for displaying the obtained images at a rate of 50 frame/second or more, and image renewal system 104 for taking in coordinate information of the cross-section to be imaged from devices 52 and 53 at intervals of about 0.1 second, and renewing the cross-section to be imaged in real time.

Abstract: To efficiently generate an accurate morphological image and the temperature change distribution image, a pulse sequence for acquiring a plurality of echo signals having different echo times is executed, while excited spins are encoded with the same phase. Among thus obtained plural echo signals, the echo signal 405 acquired in the echo time TE1 suitable for obtaining morphological information (anatomic information) is used to reconstruct a morphological image. Further, the PPS method is applied to the echo signal 406 acquired in the echo time TE2 suitable for thermometry so as to generate the temperature change distribution image. The echo signal used for generating the morphological image may be a spin echo signal or a gradient echo signal.

Abstract: An MRI apparatus and method in which image data is produced using NMR signals obtained in plural measurements performed at different times respectively. Data is calculated indicating temperature distribution within the object for image data of each measurement time and spatial discontinuity of the calculated temperature distribution data is corrected. Temperature change distribution within the object between different measurement times is calculated by subtracting the corrected temperature distribution data of each measurement time, and the calculated temperature change distribution is transformed to indicative data for supply to a display for display.

Abstract: Variations in spatial phase distribution due to static magnetic field changes are corrected based on phase variations at points, specifically, at three points or a plurality of points selected by ROI, in an area where no temperature change is encountered. And a temperature distribution image is determined by using a spatial phase distribution reflecting only temperature changes after the correction, thereby high-accuracy temperature distribution image information is provided.

Abstract: In a multi-shot MR imaging method, a navigator echo V(kx, n) of which phase-encoding amount is 0 is generated by applying a gradient magnetic field pulse in a readout direction (x-direction) and collected at each segment. A phase shift map C(kx, n) of V(kx, n) collected in the n-th segment is produced in k-space as a function in kx-direction with V(kx, 1) collected in the first segment being the reference. Next, noises are removed from C(kx, n), and C(kx, n) is smoothed. Then, an image echo signal S(kx, n, m) collected in the n-th segment is corrected in k-space according to a smoothed phase shift map C′(kx, n) of V(kx, n) collected in the same segment, and an image echo signal S′(kx, n, m) of which phase shifts are corrected is thereby acquired. Thus, the phase shifts of the image echo signals caused by a motion in the x-direction of a patient can be precisely corrected at a high speed.

Abstract: An MRI apparatus for obtaining an image of a wide area using a multiple coil where a plural number of small receiving coils are arranged such that adjacent coils overlap spatially. An image is picked up while thinning a part of the measured data such that the low spatial frequency region of k space is dense and the high spatial frequency region of thereof is sparse. The substantial sensitivity distribution of each small receiving coil is determined using the data about the low spatial frequency region, and an image is composed using the sensitivity distribution and the measured data to produce a high resolution image having no aliasing artifact in a short time.

Abstract: A plurality of signal acquisition steps 103 to 106 are executed continuously in succession to an inversion longitudinal magnetization generation step 101 for generating inversion magnetization by applying inversion RF pulses to an object. Similar process steps are iterated in another inversion longitudinal magnetization step in a slice non-selecting mode, and the difference is determined between image data acquired by the first signal acquisition steps 103 to 106 and image data acquired by the second signal acquisition steps 107 to 110 to acquire a perfusion image. In this instance, the mode of applying the gradient magnetic field is made different in each signal acquisition step, and images of a plurality of slices are acquired. The process steps described above are iterated while the correspondence relation between an inversion time TI and a selected slice is changed. An image having different inversion times can thus be acquired within a short time for a plurality of slices.

Abstract: The MRI apparatus of the present invention performs a pulse sequence for applying successively 180° pulses 102, 103 . . . after application of a 90° pulse 101 at constant intervals and applying readout magnetic fields 111 during the interval between pairs of 180° pulses while the polarity of the magnetic field 111 is inverted several times to collect a plurality of gradient echo signals that are phase encoded differently. Here, the application of the readout gradient magnetic field is controlled such that generation of the gradient echo signals does ot coincide with generation of the spin echo signal. The image reconstruction is performed by using only T2* weighted gradient echo signals to obtain images reflecting difference in magnetic susceptibility and inhomogeneities in local magnetic fields.

Abstract: In a magnetic resonance imaging method in which after irradiating RF pulses of magnetic resonance frequencies into an object to be inspected, a sequence of detecting echo signals sequentially and a step of reconstructing an image by making use of the obtained echo signals are repeated in parallel, and an animating image is obtained by successively renewing a part of the echo signals used for reconstructing the previous image, a navigator echo is generated for every irradiation of the RF pulses and is detected, a navigator echo which serves as a reference for correcting phases of the echo signals used for the image reconstruction is successively renewed for every image, and the phases of the echo signals are corrected based on the renewed navigator echo for every image obtain the same. Thereby, a reference time for correcting object motion by making use of navigator echoes (3021, 3022) is set short and artifacts due to an object motion is reduced with an accuracy corresponding to a high temporal resolution.

Abstract: RF receiving coil device used in a magnetic resonance imaging apparatus capable of acquiring a tomographic image of an object under examination positioned in a static magnetic field along a predetermined direction including quadrature detection coils for detecting an MR signal component along a direction perpendicular to a body axis direction of the object under examination and also perpendicular to a direction of the static magnetic field, and for detecting another MR-signal component along the body axis direction.

Abstract: An inspection apparatus using nuclear magnetic resonance having arithmetic and control means for controlling a pulse sequence for detecting a nuclear magnetic resonance signal from a target to be inspected and calculating the detected signal.

Abstract: A nuclear magnetic resonance imaging apparatus and an imaging method. A slice gradient magnetic field and a first radio frequency (RF) pulse magnetic field or the first and second RF pulse magnetic fields are applied to an object so as to selectively excite nuclear spins of the object and to generate echo signals by the application of the magnetic fields. The echo signals are measured by applying to the object a read gradient magnetic field whose polarity inverses continuously at least a plurality of times. A plurality of first RF pulse magnetic fields are generated in one pulse sequence. These RF pulse magnetic fields excite the nuclear spins of a plurality of different slices, and a plurality of different slices are selected. Sets of a plurality of echo signals from different slices are defected whenever the read gradient magnetic field is applied.

Abstract: A probe for an MRI apparatus in a vertical magnetic field system including: an array coil which is formed by arranging a plurality of unit coils, which can be driven independently of one another, in a direction perpendicularly intersecting a direction of a static magnetic field; and a compensating coil which forms a magnetic field in a direction perpendicularly intersecting both a direction of a magnetic field formed by the array coil and the direction of the magnetic field, a signal detected by the array coil and a signal detected by the compensating coil being composed so as to be in phase with each other, thereby to be outputted.

Abstract: An MRI RF coil including first and second ring elements having a plurality of peripheral segments connected in ring shape which are apart from each other along a common vertical axial line. The RF coil also includes a plurality of axial conductive segments for connecting the first and second ring elements electrically to each other at the contacts of the plurality of peripheral segments with a plurality of current loops being formed by neighboring axial conductive segments and two peripheral segments connected thereby. Further, at least one control signal feeding point is positioned at any one of the peripheral segments of the first or second ring elements.

Abstract: An RF probe including: two coils for detecting MR signals which are arranged at positions which face each other at a predetermined distance; an apparatus for changing a distance between those coils; and an apparatus for reducing a high frequency coupling between the two coils which is caused due to a change in distance between the coils, in accordance with the distance between the coils.

Abstract: A radio frequency pulse to excite nuclei constituting an object to be imaged, a slice selecting gradient magnetic field pulse applied when the radio frequency magnetic field pulse is applied, a phase encoding gradient magnetic pulse, a frequency encoding gradient magnetic field pulse are applied to the object to be imaged placed in a static magnetic field. Then the generated nuclear magnetic resonance signals are detected many times to form an image of the internal structure of the object to be imaged using the detected signals. In this occasion, the amplitude of the slice selecting gradient magnetic field pulse or the width of the radio frequency pulse is changed corresponding to the amount of phase encoding given by the phase encoding gradient magnetic field pulse. In multi-slice imaging for detecting the signals from a plurality of slices spatially laminated, part of the signals are used in common between the slices adjacent to each other when two-dimensional images of those slices are reconstructed.

Abstract: In a bird cage resonator, the axial length of rungs is changed between orthogonal elements. By doing this, the real view fields of orthogonal ports A and B in the sagittal direction are changed and the sensitivity difference between both view fields is reduced. For an object with an elliptical section to be inspected such as the human body, a remarkable difference in detection sensitivity between each orthogonal ports is eliminated and the receiving sensitivity of MRI apparatus employing the QD method is improved.

Abstract: An RF probe for MRI, in which a plurality of unit coils including conductive loops having resonance capacitors and inductors connected with the conductive loops in series are arranged so as to be distant from each other with a predetermined distance, electromagnetic coupling being produced between at least two inductors to remove electromagnetic coupling between the unit coils.