SCALABLE, DIVERSITY BRANCH AMPLIFIER DESIGN IN MAGNETIC RESONANCE
Publication Date: 2014-Mar-17
The IP.com Prior Art Database
The invention proposes a technique in which scalable and diversity branch amplifiers are designed for magnetic resonance (MR) systems. Couplers are introduced into scalable design for diversity branch to excite the B1 filed in MR field. The technique eliminates use of a splitter by using couplers.
FIELD OF INVENTION
The invention generally relates to a magnetic resonance (MR) system and more particularly to a scalable and diversity branch amplifier design in MR system.
BACKGROUND OF THE INVENTION
In general, transmit
chain architecture has a trend to use diversity input signal to drive body
coil. The architecture gets elliptical magnetic field (B1) instead of
circular magnetic field (B1) as the ellipse B1 is close to body of the patient profile so that the cost of radio frequency (RF) energy is saved. Further, diversity branch configuration achieves better homogeneity.
A conventional technique uses a power splitter and phase shifter to control amplitude and phase during every branch. The technique only supports specific MR systems. However, the technique is not scalable to another kind of MR systems.
FIG. 1 depicts conventional technique for transmission chain application in magnetic resonance imaging (MRI) having a multi-channel amplifier block.
Assuming N=8, same number in 3T MR design, every single amplifier have power capability of 2 kilowatt (KW), so total output power in body coil is 16KW. If another system requires different output power, for example, 10KW instead of 16KW, the designer is required to remove three channels and use five channels amplifiers to excite the body coil. However, if the designer uses five channels, then the end of power splitter and three output ports is required to be connected with 50 ohms load to absorb redundant RF energy.
FIG. 2 depicts another conventional technique having a multi-channel diversity amplifier to excite the body coils.
The technique is another kind of architecture to excite the body coil. The designer designs independent 2KW amplifier and number of amplifiers required are based on system requirements. However, power splitter is modified according to system requirements. Also, cost of the technique is more than conventional technique explained above.
Hence there exists a need for an efficient technique for amplifier designs in MR systems.
BRIEF DESCRIPTION OF THE INVENTION
The invention proposes a technique in which scalable and diversity branch amplifiers are designed for magnetic resonance (MR) systems. Couplers are introduced into scalable design for diversity branch to excite the B1 filed in MR field. The technique eliminates use of a splitter by using coupl...