Abstract: In order to provide a gradient magnetic field application method and apparatus for preventing artifacts due to a magnetic field outside a field of view (FOV), and a magnetic resonance imaging apparatus employing such a gradient magnetic field application apparatus, in performing a plurality of RF excitations of spins of atomic nuclei within a subject to be imaged in the presence of a gradient magnetic field and producing an image based on magnetic resonance signals generated by the spins, at least the polarity of the gradient magnetic field in a first RF excitation (G90) and the polarity of the gradient magnetic field in the next RF excitation (G180) are made opposite to each other.

Abstract: In order to facilitate ultrasonic imaging in a proper condition, a correlation value is calculated between a new image frame and a previous image frame each time the new image frame is obtained; and the acoustic line density of a scan is increased/decreased, the dynamic range of echo reception is enlarged/reduced, and the frame averaging intensity of an image frame is raised/lowered in response to an increase/decrease of the correlation value.

Abstract: In order to reduce residual magnetization caused by gradient pulses, for a gradient pulse having either a positive or negative polarity, a residual magnetization reducing pulse is applied after applying the gradient pulse, or for two or more successively applied gradient pulses having different polarities, the amplitude of the gradient pulse(s) is adjusted to reduce residual magnetization thereafter.

Abstract: In order to provide a magnetic resonance signal receiving method and apparatus for performing imaging with good quality and an magnetic resonance imaging apparatus employing such a magnetic resonance signal receiving apparatus, gradient magnetic fields Gs1k and Gs2k for dephasing spins are applied with their strengths varied after each spin echo is received in line scanning.

Abstract: To reduce artifacts caused by sudden change of a phase encode amount, data Hj, Mj, and Lj having a large phase encode amount are collected, and then, when collecting data C3j−4, C3j−3, and C3j−2 having a small phase encode amount, a buffer pulse sequence having an intermediate phase encode amount (+9) or (+49) is inserted one or more times between both.

Abstract: In order to detect whether the center position of a subject is offset from a scan center and notify a human operator of the result of the detection, the subject center position is detected based on a projection profile of a parallel view at a view angle of 90° (S5). If the distance between the subject center position and the scan center exceeds a predefined range (e.g., 50 cm) (S6), a warning is displayed on a CRT to prompt the operator to adjust the position of the subject and repeat imaging (S7).

Abstract: In order to provide a projection data correction method and apparatus that prevents artifact generation in the direction which provides a low count of penetrating radiation, and a radiation tomographic imaging method employing such a projection data correction method and a radiation tomographic imaging apparatus comprising the projection data correction apparatus, projection data Proj_ij is individually corrected by a weighted addition (604, 606, 608) with an average value (602) containing the proximate data. The weight SGij of the projection data is decreased as the count of the penetrating radiation from which the projection data is derived becomes smaller.

Abstract: In order to enable the observation of a wide range of the wall surface of a three-dimensional tissue in one screen, an image providing a view from a viewpoint E1 in a field-of-view centerline direction SC with a view angle of &thgr; greater than 180° is produced and displayed.

Abstract: In order to give a physician easy access to a patient placed in an interjacent space within a vertical magnet apparatus of a vertical magnet-type MRI apparatus, support and movement mechanisms 19 are provided on respective opposing surface sides of a pair of vertical opposing magnets 11, for supporting a cradle 22 or a seat 32 of a chair on belts 18, and moving the cradle 22 or the seat 32 in the horizontal direction by motors 17 and in the vertical direction by hydraulic cylinders 13.

Abstract: The present invention aims to prevent the influence of a variation in residual magnetization due to a change in gradient or gradient magnetic field pulse. In an FSE sequence, reset pulses gys1j and gysrj each having amplitude equal to the maximum amplitude used in a phase axis are inserted into the phase axis before and behind an inversion pulse Pj.

Abstract: The present invention is directed to joint motion imaging and provides a vertical magnet type MRI system comprising a vertical magnet unit (10) having a pair of opposite vertical magnets (11), a movable table (20) provided with wheels (22) for traveling and a cradle (21) to carry a specimen laid down thereon, and capable of being moved into and moved out of a space between the pair of opposite vertical magnets (11), table locking devices (13) for locking the movable table (20) with the cradle (21) being in place between the pair of opposite vertical magnets (11), a movable chair (30) provided with wheels (32) for traveling and capable of being moved into and moved out of the space between the pair of opposite vertical magnets (11), and a chair locking device (14) for locking the movable chair (30) in place between the pair of opposite vertical magnets (11).

Abstract: In order to provide a table and an MR apparatus which allows moving of a cradle and scanning to be simultaneously performed, in a table 55 comprising a table body 57, a cradle 59 provided on the table body 57 and driving means 61 for driving the cradle 59, the driving means 61 has a hydraulic motor (i.e., a driving source utilizing fluid pressure) 69 as a driving source.

Abstract: In order to provide a projection data correction method and apparatus that prevents artifact generation in the direction which provides a low count of penetrating radiation, and a radiation tomographic imaging method employing such a projection data correction method and a radiation tomographic imaging apparatus comprising the projection data correction apparatus, projection data Projij is individually corrected by a weighted addition (604, 606, 608) with an average value (602) containing the proximate data. The weight SGij of the projection data is decreased as the count of the penetrating radiation from which the projection data is derived becomes smaller.

Abstract: In order to reduce the electric current loss and the heat release in a shielding coil, partially shielding coils 1Zts and 1Zbs are employed having their windings positioned corresponding only to a high winding density zone 1Zp, rather than corresponding to the entire winding area, of main gradient coils 1Zt and 1Zb.

Abstract: In order to accurately measure a gradient magnetic field, a pre-encoding pulse Pk is applied, data S(k, 1)-S(k, T) are collected from an FID signal while applying an encoding pulse Ge having a gradient waveform to be measured, and the above steps are repeated K times with the magnitude of the pre-encoding pulse Pk varied; data D(1,1)-D(1, T−1), D(2, 1)-D(2, T−1), . . . , D(K, 1)-D(K, T−1) having a phase difference &Dgr;&phgr; as an angle are obtained from the collected data S(1,1)-S(1, T), S(2, 1)-S(2, T), . . . , S(K, 1)-S(K, T); data having corresponding magnitudes of the encoding pulse Ge are added to obtain added data d(1)-d(T−1); gradient magnetic field differences &Dgr;G(1)-&Dgr;G(T−1) are obtained from the added data d(1)-d(T−1); and the gradient magnetic field differences &Dgr;G(1)-&Dgr;G(T−1) are integrated to obtain a gradient magnetic field G(1)-G(T−1).

Abstract: In order to provide a selective excitation method and apparatus that is not affected by the non-linearity of a gradient magnetic field, and a magnetic resonance imaging method and apparatus employing such a selective excitation apparatus, a frequency f is employed as an RF excitation frequency, corresponding to a slice position Zc redefined differently from a specified slice position Za according to a non-linearity error in a gradient magnetic field Gz. Alternatively, the gradient is adjusted so that the frequency of spins at a specified slice position Za equals to a frequency f of the RF excitation signal.

Abstract: In order to allow slice thicknesses to be set for a twin asymmetric scan in which a scan is performed with a first slice thickness in a first detector row of a multi detector and with a second slice thickness different than the first slice thickness in a second detector row, first, a position of an X-ray beam is moved and a scan is performed while keeping the width of the X-ray beam fixed at twice the first slice thickness to move the position of the X-ray beam to a position at which count values for the first and second detector rows match (ST2-ST5). The count value for the detector row at this time is stored (ST6). Next, the position of the X-ray beam is moved and a scan is performed while keeping the width of the X-ray beam fixed at the sum of the first and second slice thicknesses to move the position of the X-ray beam to a position at which the count value for the first detector row matches the stored count value (ST7-ST9).

Abstract: An RF coil which is a coil array using three pieces or more of coils, including three pieces of coils 1, 2 and 3 or more arrayed proximately to each other, coil intermediary connecting capacitors 4, 5 and 6 respectively interposed in the coils, parallel connection lines 10 through 13 for connecting the coil intermediary connecting capacitors 4, 5 and 6 in parallel and neutralizing capacitors 14 through 17 interposed in the parallel connection lines 10 through 13 with an object of dispensing with mutual interference among the coils without overlapping the adjacent coils, in which by transmitted voltage transmitted from both ends of the coil intermediary connecting capacitor (4) of the one coil (1)to both ends of the coil intermediary connecting capacitors (5, 6)of the other coils (2, 3)via the parallel connection lines (10 through 13)and the neutralizing capacitors (14 through 17), induced voltage generated by the one coil (1) across the both ends of the coil intermediary connecting capacitors (5, 6)of the oth

Abstract: With a view of facilitating the manufacture and reducing the cost, a pulley according to the present invention comprises an annular portion 100 formed by laminating rings 110, 120 and 130 and a tooth portion formed along a circumferential surface of the annular portion 100, the tooth portion comprising a plurality of resin teeth having blades formed on the side opposite to the side which is opposed to the circumferential surface of the annular portion. The rings 110, 120 and 130 are divided into a plurality of arcuate plates 111, 112, 113, 121, 122, 123, 131, 132 and 133.

Abstract: In order to provide a receive coil comprising a plurality of coils that make no coupling, and a magnetic resonance imaging method and apparatus employing such a receive coil, when a receive coil is formed by disposing a plurality of loops of conductor 424 having series capacitors 422, a low input-impedance amplifier 426 is provided with its input circuit connected in parallel to both ends of the capacitor 422 via an inductor 428 to achieve decoupling between the loops by a high impedance caused by parallel resonance of an LC circuit.