Abstract: In order to provide a spin excitation method and apparatus for performing imaging with good efficiency while keeping within an SAR limit, and a magnetic resonance imaging apparatus employing such a spin excitation apparatus, an SAR of an object to be imaged in executing a pulse sequence is predicted (704); and at least one among the number of pulses, pulse waveform and pulse width of the RF pulses in the pulse sequence is adjusted (706) so that the predicted SAR value falls within a predetermined limit.

Abstract: Proposed is an improvement in an opposed-magnet magnetic circuit assembly with permanent magnets suitable for use, for example, in an MRI instrument comprising a pair of upper and lower permanent magnets to form a magnetic-field gap space therebetween, a pair of magnetic-field adjustment plates each on the surface of the permanent magnet to face the gap space and a pair of back yokes each on the back surface of the permanent magnet. According to the first aspect of the invention, a combination of a gradient coil and a shimming plate is mounted on the magnetic-field adjustment plate with intervention of several pieces of shim members and, further, another set of second shim members are bonded to the surface of the shimming plate facing the gap space with an object to improve the uniformity of the magnetic field in the gap space.

Abstract: Proposed is an improvement in an opposed-magnet magnetic circuit assembly with permanent magnets suitable for use, for example, in an MRI instrument comprising a pair of upper and lower permanent magnets to form a magnetic-field gap space therebetween, a pair of magnetic-field adjustment plates each on the surface of the permanent magnet to face the gap space and a pair of back yokes each on the back surface of the permanent magnet. According to the first aspect of the invention, a combination of a gradient coil and a shimming plate is mounted on the magnetic-field adjustment plate with intervention of several pieces of shim members and, further, another set of second shim members are bonded to the surface of the shimming plate facing the gap space with an object to improve the uniformity of the magnetic field in the gap space.

Abstract: The present invention relates to an MRI apparatus capable of preventing the quality of an image from being degraded under the influence of eddy currents and residual magnetization caused by a phase encode gradient. While an RF pulse P1 is sent, a phase encode gradient gy(i) is applied to a warp axis and a read gradient rr is applied to a read axis, an NMR signal is received, followed by application of a rewind gradient gyr(i)' to the warp axis. The rewind gradient gyr(i)' is defined as "(a basic component of opposite polarity equal in time integral value to the phase encode gradient gy(i))+(a warp-axis correction component for correcting the influence of eddy currents or residual magnetization caused by the phase encode gradient gy(i))".

Abstract: A digital phase shifting apparatus wherein the phase of a train of sampled digital-data is changed by a fine step shorter than a sampling period using a sampling signal with a fixed phase or a clock signal, the apparatus comprising:a memory unit for storing the time-axis train of sampled digital data one after another at addresses corresponding to sampling times;a memory read device for reading out digital data sampled at times ahead of a current sampling time by desired time differences from the memory unit one sampled data after another in synchronization with an operation to sample the time-axis train of sampled of digital data;registers for holding sampled digital data read out from the memory unit, from a most recently read data to a data ahead of the most recently read data sampled data by a predetermined piece count; andan interpolated-data generating device for summing up a plurality of sampled data held in the registers with a weight applied to each of the data to generate interpolated data at a desi

Abstract: A plurality of ultrasonic pulses are transmitted to the inside of a living body by an ultrasonic probe and an ultrasonic echo signal is received from within the living body. An auto-correlating unit effects auto-correlation processing on the ultrasonic echo signal to produce a real-part component and an imaginary-part component. A real-part component corrector adds an offset value to the real-part component so as to generate a new real-part component. A velocity detector detects a moving velocity of a tissue or blood from the new real-part component and the imaginary-part component.

Abstract: This invention realizes an ultrasonic probe wherein wiring is substantially eliminated between piezoelectric vibrators and signal sending/receiving circuits in the probe. The ultrasonic probe comprises a vibrator array and a semiconductor wafer on which signal sending/receiving circuits for the vibrator array are integrated, with the wafer being glued to the vibrator array by means of conductive adhesive. Fabricated by being integrated on the semiconductor wafer are signal sending/receiving circuits for individual piezoelectric vibrators positioned coincidently to the arrangement of signal electrodes of the piezoelectric vibrators of the ultrasonic probe, and each signal sending/receiving circuit has a conductive buried layer, which is in connection with the output terminal of the sending circuit and the input terminal of the receiving circuit, exposed to the semiconductor wafer on the side of the vibrator array glued surface.