摘要:
In an image reconstruction method in a nuclear magnetic resonance imaging apparatus, the method comprises first and second steps to get detected data S.sub.I for at least about half of region inclusive of an origin and data S.sub.IV in a region symmetric with respect to a line passing through an origin on one of axes from the detected region in the acquired data space and parallel to the other axis, respectively, third and fourth steps to perform inverse Fourier transform on the data S.sub.I and S.sub.IV, respectively, a fifth step to get a complex conjugate value of the result obtained from Step 3, a sixth step to get a complex conjugate value of the result obtained from Step 4, a seventh step to calculate a phase map from the results obtained from the second, third, fourth, fifth and sixth steps, an eighth step to multiply the result obtained from step 6 by the phase map obtained from step 7 and to obtain a phase corrected data, and a ninth step to sum the result obtained from the third step and the result obtained from the eighth step. The method can thus obtain the whole reconstructed image.
摘要:
In a magnetic resonance imagining method, using an effect that a fluid flows out of a plane where it is selectively excited between the time of applying a 90.degree. radio frequency pulse and the time of applying of a 180.degree. radio frequency pulse, two, images are separately constructed from multiple echo signals which are sampled before applying the 180.degree. radio frequency pulse and multiple echo signals which are sampled after applying the 180.degree. radio frequency pulse. An image of the fluid flow and an image of a static part are separated from each other based on a difference between the two constructed images.
摘要:
An ultrasonic probe includes a resonator made of a piezoelectric ceramic material which is obtained by subjecting a ceramic composition containing 44.7 to 46.3 mol % of PbO, 50.9 to 51.7 mol % of TiO.sub.2, 1.8 to 2.7 mol % of Sm.sub.2 O.sub.3 and 0.5 to 1.0 mol % of MnO.sub.2 to poling treatment in such a manner that the ceramic composition is applied with an electric field of 60 to 80 kV/cm at a temperature of 130.degree. to 160.degree. C.
摘要翻译:超声波探头包括由压电陶瓷材料制成的谐振器,该共振器通过使含有44.7〜46.3摩尔%的PbO,50.9〜51.7摩尔%的TiO 2,1.8〜2.7摩尔%的Sm 2 O 3和0.5〜1.0摩尔%的陶瓷组合物, 的MnO 2以使陶瓷组合物在130〜160℃的温度下施加60〜80kV / cm的电场的方式进行极化处理。
摘要:
A coil component includes a conductor film provided on the surface of a core having flanges. On one flange, first and second dividing grooves and a connecting groove are provided, whereby first and second terminals are defined. On the other flange, third and fifth dividing grooves and a connecting groove are provided, whereby third and fourth terminals are defined. First and second winding-around grooves are connected to the respective dividing grooves and arranged substantially parallel to each other. A coil connected to the first and third terminals and a coil connected to the second and fourth terminals are also provided.
摘要:
In an inspecting method based on nuclear magnetic resonance, a burst wave having a plurality of sub-pulses frequency-modulated with a high frequency is generated, the burst wave is amplitude-modulated with at least a function which repeats polarity inversion, the amplitude-modulated burst wave is irradiated, as an exciting high frequency pulse, to an object to be inspected, and gradient magnetic fields are generated in predetermined pulse sequence to measure a nuclear magnetic resonance signal.
摘要:
An inspection method by means of an inspection apparatus using nuclear magnetic resonance and having magnetic field generating apparatus for generating a static magnetic field, gradient magnetic fields and an RF magnetic field; magnetic field generating apparatus by means of additional shim coils, which vary homogeneity of the static magnetic field by varying current flowing therethrough; signal detecting apparatus for detecting nuclear magnetic resonance signals from an object to be inspected; an apparatus for processing signals detected by the signal detecting apparatus; and control apparatus for controlling currents flowing through the shim coils, which method using nuclear magnetic resonance comprises a step of storing shim currents corresponding to each of a plurality of slices, capable of improving homogeneity of the static magnetic field for each of the plurality of slices, and a step of switching over the shim currents to those corresponding to a relevant slice to be measured prior to measurements of nuclear magnetic resonance signals from the slice. This inspection method can be applied also to a case where measurements of other slices are effected in intervals of measurements of the relevant slice.
摘要:
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.
摘要:
A bobbin for holding a gradient magnetic field coil, having a changeable size and sectional shape (a separable bobbin) is constituted by assembling coil supporters (a bobbin divided into a plurality of segments). The separable bobbin has coil supporters of an upper part a bottom part and a set of side surface parts and at least two supporting rods made of a nonmagnetic substance are fitted to the side surface parts of the coil supporters. Holes permitting the insertion of the supporting rods are bored in the upper and bottom parts of the coil supporters. The length d1 between both side surface parts can be made variable by adjusting the insertion length of the supporting rod into the upper and bottom parts. Accordingly, the distance between a patient and a gradient magnetic field can be reduced, and an intended gradient magnetic field intensity can be generated by a smaller current producing the gradient magnetic field than in the prior art. Setting of the patient to an MRI imaging apparatus becomes also easier, and there can be obtained a gradient magnetic field coil capable of being easily fitted and removed to and from the MRI imaging apparatus.
摘要:
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.
摘要:
A nuclear magnetic resonance apparatus receives nuclear magnetic resonance signals from an object under test with an RF probe which is an array of coils, implements down-frequency conversion with frequency converters for the received signals in multiple channels such that the frequency bands of the converted signals do not virtually overlap, filters the converted signals with band pass filters each operating to cut off frequency bands of other channels, hybridizes the filtered signals of multiple channels to form a hybridized signal, and produces an image from the hybridized signal.