Kabushiki Kaisha Toshiba

Toshiba Medical Systems Corporation

Hiroshi Hayakawa

Sadanori Tomiha

Masatoshi Hanawa

Kazuyuki Soejima

Manabu Ishii

Toru Aratani

Tomoyuki Yoshida

In one embodiment, an MRI apparatus includes receiving coils each including an A/D converter configured to convert an MR signal received from an object into a digital signal by sampling the MR signal, a clock generation circuit configured to generate a reference clock of the sampling, and a radio transmission circuit configured to wirelessly transmit a digitized MR signal; and a main body configured to wirelessly receive the digitized MR signal and generate an image of the object by reconstructing the digitized MR signal, wherein one of the receiving coils selected as a reference receiving coil by the main body is configured to transmit the reference clock to each of other receiving coils by radio or by wire; and each of the other receiving coils is configured to synchronize the reference clock generated by the clock generation circuit with the reference clock transmitted from the reference receiving coil.

MRI apparatus

According to one embodiment, an MRI apparatus includes a first RF coil device, a radio communication unit and an image reconstruction unit. The first RF coil device is wirelessly connected to a second RF coil device, and receives a nuclear magnetic resonance signal wirelessly transmitted from the second RF coil device. The first RF coil device wirelessly transmits the nuclear magnetic resonance signal detect by the first RF coil device and the nuclear magnetic resonance signal obtained from the second RF coil device to the radio communication unit, via an induced electric field. The radio communication unit receives the nuclear magnetic resonance signals wirelessly transmitted from the first RF coil device via an induced electric field. The image reconstruction unit reconstructs image data on the basis of the nuclear magnetic resonance signals received by the radio communication unit.

Magnetic resonance imaging apparatus and RF coil device

A magnetic attraction preventive system includes an approach detection unit which generates an approach detection magnetic field and detects the approach of a magnetic material to a magnetic resonance imaging apparatus on the basis of a variation in the strength of the approach detection magnetic field, and a preventive unit which prevents magnetic attraction of the magnetic material to the magnetic resonance imaging apparatus when the approach detection unit detects the approach of the magnetic material to the magnetic resonance imaging apparatus.

Magnetic attraction preventive system

A magnetic resonance imaging apparatus capable of freely performing the presaturation in a wide-range region over the excited region of the transmiteceive coil and also capable of sufficiently suppressing the blood-flow artifact and the motion artifact to a minimum. The magnetic resonance imaging (MRI) apparatus includes: a static magnetic field generating unit; a gradient magnetic field generating unit where the gradient magnetic field is overlapped to the static magnetic field; a sequencer for executing a desired pulse sequence, in which the pulse sequence includes a main sequence that detects a magnetic resonance signal, and a pre-saturation sequence that saturates magnetization in a biological body under medical examination, prior to execution of the main sequence; first radiofrequency (RF) coil for transmitting a high frequency magnetic field to the biological body according to the main sequence; and second (RF) coil for transmitting a high frequency magnetic field to perform pre-saturation according to the presaturation sequence.

Magnetic resonance imaging (MRI) apparatus employing optimum

An RF coil for MRI apparatus is provided which comprises a dielectric unit, such as a bobbin, plurality of coil conductors formed on the outer peripheral surface of the dielectric unit in a mutually adjacent relation to generate a magnetic field, and frame, such as a guard ring, provided on the inner surface of the dielectric unit to define a bobbin portion of the dielectric unit. An accommodation space is provided inside the bobbin to located a living substance to be examined, allowing an RF wave to be transmitted and received to and from the subject in the accommodation space. A plurality of openings are provided in the dielectric unit per se at a location of the bobbin portion. By so doing, it is possible to reduce an induction loss in the bobbin portion which would otherwise be damaging to the electrical function of the RF coil and to obtain an RF coil of an improved Q-factor.

RF-coil for MRI apparatus

The magnetic resonance imaging system applies a uniform static magnetic field and a gradient magnetic field to an object and further applies an excitation rotating magnetic field to cause magnetic resonance phenomena in the object to detect the induced magnetic resonance signals and then to obtain image data by processing the magnetic resonance signals. The system has a power controller for controlling the transmission power in a transmitter for transmitting the excitation rotating field. The system further has a transmission controller for controlling the power controller in response to the magnetic resonance signal which is received by the receiver from the object. The transmission controller controls the power controller to sequentially change the transmission power and detects the transmission power at which the maximum magnetic resonance signal is obtained in response to the reception signal by the receiver when the excitation rotating field is applied to the object, thereby controlling the power controller in accordance with the detected data. A fraction of the detected maximum power is utilized to generate the excitation field to thereby rotate the spin angle of the nuclei by an amount less than 90.degree., and preferably 45.degree., so as to reduce data collection time.

Magnetic resonance imaging system

The magnetic resonance imaging system applies a uniform static magnetic field and a gradient magnetic field to an object and further applies an excitation rotating magnetic field to cause magnetic resonance phenomena in the object, and detects the induced magnetic resonance signals and then obtains image data by these magnetic resonance signals. The system has a power controller for controlling the transmission power in a transmitter for transmitting the excitation rotating field. The system further has a transmission controller for controlling the power controller in response to the magnetic resonance signal which is received by the receiver from the object. The transmission controller controls the power controller to sequentially change the transmission power and detects the transmission power at which the maximum magnetic resonance signal is obtained in response to the reception signal by the receiver when the excitation rotating field is applied to the object, thereby controlling the power controller in accordance with the detected data.

Growing community of inventors

Otawara, Japan

Hiroshi Hayakawa