Magnetic resonance imaging apparatus and apparatus for measuring radio frequency output for the same

Patent metadata

Field	Value
Publication number	US-2017371011-A1
Application number	US-201715681040-A
Country	US
Kind code	A1
Filing date	Aug 18, 2017
Priority date	Sep 25, 2012
Publication date	Dec 28, 2017
Grant date	—

Abstract

An apparatus for measuring radio frequency output for a magnetic resonance imaging apparatus includes a plurality of directional couplers, a comparator, a switcher and a converter. The plurality of directional couplers are different in degree of coupling from each other, and attenuate an RF signal which is generated in an RF signal generator and amplified in an RF power amplifier. The comparator compares input-level information of a signal inputted into the RF power amplifier with a threshold value. The switcher switches to any one of the plurality of the directional couplers based on a result of the comparison so as to output an RF signal by the one directional coupler. The converter performs a digital conversion of the RF signal from the one directional coupler so as to output a digital signal.

First claim

What is claimed is:

1 . An apparatus for measuring radio frequency output for a magnetic resonance imaging apparatus, comprising:
a directional coupler variable in degree of coupling, and configured to attenuate a radio frequency signal which is generated in a radio frequency signal generator and amplified in a radio frequency power amplifier; a signal controller configured to control the degree of coupling of the directional coupler; and a converter configured to perform a digital conversion of the radio frequency signal from the directional coupler so as to output a digital signal.

2 . The apparatus for measuring radio frequency output according to claim 1 , wherein
the signal controller controls the degree of coupling of the directional coupler based on the input-level information of the signal inputted into the radio frequency power amplifier.

Assignees

• Toshiba Medical Sys Corp

Inventors

• Nakamura Haruki
• Soejima Kazuyuki
• Kato Sojiyuuro

Classifications

• A61B5/704

  Tables · CPC title

• A61B5/055 Primary

  involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging · CPC title

• A61B5/7203

  for noise prevention, reduction or removal · CPC title

• A61B5/0037

  Performing a preliminary scan, e.g. a prescan for identifying a region of interest · CPC title

• G01R33/3607

  RF waveform generators, e.g. frequency generators, amplitude-, frequency- or phase modulators or shifters, pulse programmers, digital to analog converters for the RF signal, means for filtering or attenuating of the RF signal · CPC title