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1. (WO2004060156) MAGNETIC RESONANCE IMAGING DEVICE

Pub. No.:    WO/2004/060156    International Application No.:    PCT/JP2003/016560
Publication Date: Fri Jul 23 01:59:59 CEST 2004 International Filing Date: Thu Dec 25 00:59:59 CET 2003
IPC: G01R 33/483
G01R 33/54
Applicants: HITACHI MEDICAL CORPORATION

TAKAHASHI, Tetsuhiko

TAKEUCHI, Hiroyuki

TAKIZAWA, Masahiro

Inventors: TAKAHASHI, Tetsuhiko

TAKEUCHI, Hiroyuki

TAKIZAWA, Masahiro

Title: MAGNETIC RESONANCE IMAGING DEVICE
Abstract:
There is provided an MRI device preferable for realizing a selective excitation method (parallel transmission) using a plurality of RF transmission coils. The MRI device includes an RF transmission coil (104) consisting of a loop coil (210), a primary differentiation coil (220), and a secondary differentiation coil (230) sharing a center line (210) as an RF reception coil or an RF transmission coil. When performing imaging, the coils (210, 220, 230) constituting the RF transmission coil (104) are simultaneously driven by the in-phase RF signal and at the latter half of radiation time, only the differentiation coils (220, 230) are driven with a phase different from the first half by 180 degrees. Alternatively, two measurements are used in a pair as follows. At the first measurement, the coils (210, 220, 230) are simultaneously driven by the in-phase RF signal. At the second measurement, only the differentiation coils (220, 230) are driven with the phase inverse to the first measurement. The measured signals are added, respectively. The result of such imaging or the addition result of the two measurements gives a profile for exiting a local region. Thus, it is possible to selectively excite only a desired region without using an RF pulse for signal suppression.