Method and apparatus for mapping lines of nuclear density within an object using nuclear magnetic resonance
Impulse resonance spectrometer
Use of phase alternated RF pulses to eliminate effects of spurious free induction decay caused by imperfect 180 degree RF pulses in NMR imaging
Nuclear magnetic resonance imaging using pulse sequences combining selective excitation and driven free precession
Method for measuring the nuclear magnetic resonance
Imaging apparatus using nuclear magnetic resonance
ApplicationNo. 07/052874 filed on 05/22/1987
US Classes:324/314, With conditioning of transmitter signal324/309To obtain localized resonance within a sample
ExaminersPrimary: Levy, Stuart S.
Assistant: O'Shea, Kevin D.
Attorney, Agent or Firm
International ClassesG01R 33/48 (20060101)
G01R 33/58 (20060101)
G01R 33/32 (20060101)
G01R 33/36 (20060101)
Foreign Application Priority Data1985-02-19 JP
AbstractThe 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°, and preferably 45°, so as to reduce data collection time.