Abstract:
Regardless of the measurement conditions, the degradation of the image quality due to a vibrational error magnetic field, which is generated by the vibration of the mechanical structure of an MRI apparatus, is reduced. In order to do so, error magnetic field image data indicating an error magnetic field distribution is acquired on the basis of an echo signal measured using a pulse sequence having a test gradient magnetic field, a parameter value of a damped vibration function showing a vibrational error magnetic field is calculated using the error magnetic field image data, and a correction magnetic field is calculated on the basis of the calculated parameter value of the damped vibration function showing the vibrational error magnetic field.
Abstract:
There is provided a technique for securing a comfortable examination space in a tunnel type MRI apparatus without increasing the manufacturing cost of the MRI apparatus and sacrificing performance thereof. In an RF coil provided with a hollow-shaped outer conductive element and a strip-shaped conductive element disposed along the outer conductive element in the axial direction, meander lines constituting the strip-shaped conductive element are disposed at uneven distances from the outer conductive element to secure an internal space. In order to obtain uniform sensitivity at the center of the RF coil, the strip-shaped conductive element is constituted with N of connected meander lines, and length of the strip-shaped conductive element is adjusted so that, in the strip-shaped conductive element resonating at resonance frequency of the antenna, nodes are formed in a number of (M+1)×N−1, wherein M is 0 or a natural number of 1 or larger.
Abstract:
A magnetic resonance imaging device includes a predetermined pulse sequence, the predetermined pulse sequence including an unnecessary material suppressing sequence unit for canceling a signal from an unnecessary material which is not a measurement target and a main imaging sequence unit for measuring a nuclear magnetic resonance signal used to create an image of an examinee. The unnecessary material suppressing sequence unit generates at least two or more high frequency magnetic field pulses so that the longitudinal magnetization of the unnecessary material is made spatially uniform in the imaging space under application of a first high frequency magnetic field pulse in the main imaging sequence unit.
Abstract:
A golf club 2 is provided with a head 4, a shaft 6, and a ferrule 8. The head 4 has a hosel hole 22. The hosel hole 22 has a large-diameter part 24 and a small-diameter part 26. The ferrule 8 has a base part 30 interposed between the large-diameter part 24 and the shaft 6. The large-diameter part 24 is disposed coaxially with the small-diameter part 26. The shaft 6 has a tip end surface 40 disposed in the small-diameter part 26. The large-diameter part 24 has an axial directional length longer than that of the small-diameter part 26. Preferably, the base part 30 has an end surface 52 separated from the bottom surface 54 of the large-diameter part 24. Preferably, an adhesive v1 is disposed in an enclosed part 62 defined by the end surface 52 of the base part 30, the bottom surface 54 of the large-diameter part 24, the outer peripheral surface 58 of the shaft 6, and the inner peripheral surface 60 of the large-diameter part 24. The shaft 6 and the large-diameter part 24 are bonded by the adhesive v1.
Abstract:
A magnetic resonance imaging device includes magnetic field generating means and control means for controlling receiving means according to a predetermined pulse sequence, the predetermined pulse sequence including an unnecessary material suppressing sequence unit for canceling a signal from an unnecessary material which is not a measurement target and a main imaging sequence unit for measuring a nuclear magnetic resonance signal used to create an image of an examinee. The unnecessary material suppressing sequence unit generates at least two or more high frequency magnetic field pulses so that the longitudinal magnetization of the unnecessary material is made spatially uniform in the imaging space under application of a first high frequency magnetic field pulse in the main imaging sequence unit. The magnetic resonance imaging device further includes adjusting means for adjusting the flip angles of the two or more high frequency magnetic field pulses, and the control means applies the two or more high frequency magnetic field pulses at the flip angles adjusted by the adjusting means.
Abstract:
A magnetic resonance imaging device includes control means for controlling receiving means according to a predetermined pulse sequence that includes an unnecessary material suppressing sequence unit for suppressing a signal from an unnecessary material which is not a measurement target, and a main imaging sequence unit for measuring a nuclear magnetic resonance signal used to create an image of an examinee. The unnecessary material suppressing sequence unit generates at least two or more high frequency magnetic field pulses so that the longitudinal magnetization of the unnecessary material is made spatially uniform in the imaging space under application of a first high frequency magnetic field pulse in the main imaging sequence unit.
Abstract:
Disclosed is an edible oil which is hardly deteriorated by oxidation and therefore has excellent storage stability. Also disclosed is a method for producing the edible oil. A nitrogen gas in the form of nanobubbles each having a diameter of less than 1000 nm (1 μm) and microbubbles each having a diameter of 1 to 350 μm (inclusive) is added to an edible oil. In this manner, it becomes possible to produce an edible oil having a content of nitrogen in the oil or a content of dissolved nitrogen in the oil of 4.5% (by volume) or more and an edible oil containing nitrogen nanobubbles each having a diameter of less than 1000 nm (1 μm) and nitrogen microbubbles each having a diameter of 1 to 350 μm (inclusive).
Abstract:
An MRI apparatus excellent in magnetic field generation efficiency is provided. According to this invention, a main coil (52) of a gradient magnetic field coil (13) is partially recessed to reduce the total thickness of a radio-frequency coil (11) and a gradient magnetic field coil (13). That is, the main coil (52) is designed in a tubular shape, and the diameter r1 at the center portion of the imaging space is larger than the diameter r2 of the main coil end portion. Accordingly, the RF coil (11) can be disposed to be near to the gradient magnetic field coil (13) side without lowering the magnetic field generation efficiency.
Abstract:
A golf club shaft having at least six full-length layers composed of prepregs. The full-length layers are divided into an inner-layer part including a half of the full-length layers and an outer-layer part including a remaining half of the full-length layers. At least one pair of the full-length layers is formed as a bias set layer in each of the inner-layer part and the outer-layer part by layering two bias layers with each other, with reinforcing fibers of the bias layers intersecting with each other at an orientation angle of ±θ° which fall in a range from ±25° to ±65° with respect to an axis of the golf club shaft. A straight layer is formed as an outermost full-length layer of the outer-layer part with reinforcing fiber thereof orienting at the range from 0° to ±10° with respect to the axis of the shaft.
Abstract:
An MRI apparatus capable of selecting an optional direction as a phase encoding direction and achieving a preferable S/N, when an imaging time shortening technique is applied. A receiver coil, used as a receiver coil of a vertical magnetic field MRI apparatus, is a combination of a first coil (solenoid coil) forming a current loop around the outer circumference of a test object, second coils forming even-numbered current loops, and third coils forming odd-numbered current loops, in the direction intersecting the plane of the current loop of the first coil. The second coil and the third coil are arranged in such a manner that, as for the current loops in the array direction thereof, a position where a sensitivity of one coil is minimized approximately coincides with a position where the sensitivity of the other coil is maximized, whereby electromagnetic coupling is suppressed.