摘要:
In the magnetic resonance imaging device, the distance between the first and second coils is different in the circumferential direction and has a first region (A1) (θ=0, π) and a second region (A2) (θ=π/2) narrower than the first region (A1). In the first coil, wiring patterns (17a, 17b) on the side of a zero-plane (F0) passing through the center of the first coil and perpendicular to the axis direction (z-axis direction) meander in the circumferential direction such that the wiring patterns (17a, 17b) depart from the zero-plane (F0) in the first region (A1) and approach the zero-plane (F0) in the second region (A2). This provides a gradient magnetic field coil capable of configuring wiring patterns without using a loop coil that does not pass through the z-axis.
摘要:
An object is to correct a magnetic field caused by an eddy current, which is generated due to application of a gradient magnetic field, not only in the application direction of the gradient magnetic field but also in a direction different from the application direction of the gradient magnetic field. In the present invention, in order to achieve this object, a compensation magnetic field which compensates for an eddy current magnetic field generated in each of an application direction of a test gradient magnetic field and a direction different from the application direction in each direction is calculated using the test gradient magnetic field. When generating an arbitrary gradient magnetic field, a compensation magnetic field which compensates for an eddy current magnetic field according to application of an arbitrary gradient magnetic field on the basis of the measured eddy current magnetic field in each direction is generated together with the arbitrary gradient magnetic field.
摘要:
There is provided a coil unit having a large region of homogeneous sensitivity for the axial direction even with a shortened rung length of birdcage type RF coil.The coil unit comprises a gradient coil which is disposed along a static magnetic field generating source, and a radio frequency coil which is disposed along the gradient coil in a test region at a position closer to the center of the test region compared with the gradient coil, and a conductor part which is disposed between the gradient coil and the radio frequency coil, and covers periphery of the radio frequency coil. The radio frequency coil comprises a first loop coil and a second loop coil locating in planes substantially perpendicular to direction of the static magnetic field, a plurality of linear conductors connecting the first loop coil and the second loop coil and substantially parallel to the direction of the static magnetic field, and a plurality of first capacitors disposed in the first loop coil and the second loop coil. The coil unit further comprises a first connecting part, which electrically connects the radio frequency coil and the conductor part via a second capacitor and comprises an electric power supply circuit disposed in parallel to the second capacitor, and a second connecting part which connects the radio frequency coil and the conductor part via a third capacitor.
摘要:
Disclosed is an oil-and-fat composition having a high α-linolenic acid content, a hypertension-ameliorating effect, a good flavor, and good storage stability. Also disclosed is a food or beverage containing the oil-and-fat composition. The oil-and-fat composition comprises at least one plant oil A selected from flax oil, perilla oil and perilla seed oil, rice oil, and at least one plant oil B selected from rape seed oil, soybean oil and corn oil at a ratio among the plant oil A, rice oil and the plant oil B [i.e., a (plant oil A)/(rice oil)/(plant oil B) ratio] of 20-35/15-25/40-65 by mass, wherein the α-linolenic acid content in the constituent fatty acids contained in the oil-and-fat composition is 15 to 30 mass %.
摘要:
A magnetic resonance imaging apparatus capable of suppressing noise caused by vibration of a gradient magnetic field coil and improving image quality includes a large number of ferromagnetic shims disposed in a large number of holes formed in a shim tray, and vibration dampers disposed in holes formed in the shim tray to reduce noise generated by vibration of a gradient magnetic field generating coil.
摘要:
An aldehyde derivative represented by the general formula (2) is reacted with ketene in the presence of a Lewis acid catalyst to produce a novel 2-oxetanone derivative (1), which is then purified to a 2-oxetanone derivative having a high trans-isomer purity, and then converted to a vinyl derivative (3) through decarboxylation reaction.
摘要:
A magnetic resonance imaging apparatus capable of suppressing noise caused by vibration of a gradient magnetic field coil and improving image quality is realized.A shim tray 22 is disposed between a static magnetic field generating magnet 4 and a gradient magnetic field generating coil 13. A large number of ferromagnetic shims are disposed in a large number of holes (screw holes) 24 formed in the shim tray 22. Vibration dampers 23 are disposed in holes formed in the shim tray 22 to reduce noise generated by vibration of the gradient magnetic field generating coil 13, which is propagated to the static magnetic field generating magnet through solid bodies and shakes the static magnetic field generating magnet, etc. It is hence possible to secure areas for arrangement of two means, i.e., static magnetic-field non-uniformity correcting means and vibration suppressing means, to reduce the noise caused by the vibration of the gradient magnetic field generating coil 13, and to suppress deterioration of image quality.
摘要:
A golf club grip includes: a grip body including a grip cylinder portion and a grip end portion disposed at one end of the grip cylinder portion and formed with a through-hole for communicating a grip interior with the outside; and a vibration absorption member formed from a viscoelastic material and formed separately from the grip body. The vibration absorption member is removably attached to the grip body. The vibration absorption member includes: a plane portion and a bar-like portion formed integrally with the plane portion. The bar-like portion extends through the through-hole of the grip end portion as projecting inwardly of the grip cylinder portion.
摘要:
A magnetic resonance imaging method comprising a step for applying one or more gradient magnetic field pulses continuously, a step for calculating a residual magnetic field being generated from a magnet by an gradient magnetic field pulse based on a residual magnetic field response function representing the relation between the strength of the gradient magnetic field pulse being applied and the strength of a residual magnetic field being generated, and a step for correcting the residual magnetic field thus calculated. The magnetic resonance imaging method is further provided with a step for updating the residual magnetic field response function with time depending on the application history of the gradient magnetic field pulses being applied continuously.
摘要:
A racket frame including a grip part, a shaft part, a throat part, and a head part formed hollowly with a fiber reinforced resin and having a weight not less than 100 g nor more than 270 g. The racket frame is provided with a dynamic damper comprising a mass member and a viscoelastic member mounted on a part of a peripheral surface of the mass member. The dynamic damper is mounted inside the grip part by fixing the viscoelastic member to a position of an inner wall of the grip part located within a range of 0.2 L from a free end of the grip part, supposing that a whole length of the racket frame is L in such a way that inside the grip part, at least one part of the mass member is shakable with respect to the inner wall of the grip part.