[Evaluation of the Effect of Adiabatic Pulse and B1 Shim to the Radio Frequency Homogeneity in Chemical Shift Imaging].
It is considered that the enhancement of chemical shift and the elevation of signal-to-noise ratio (SNR) induced by high magnetic fields are useful for the evaluation of metabolism using magnetic resonance spectroscopy (MRS). However, the reduction of the localization in MRS seems to be caused by the decreased homogeneity of radio frequency (RF) pulses, especially in chemical shift imaging (CSI). To search the influence of B1 shim mode and the significance of adiabatic pulses, we have examined the changes of RF homogeneity using 3 T magnetic resonance imaging (MRI) with the water phantom and the metabolites phantom (containing acetate and lactate) in CSI. The RF homogeneity and chemical shift artifact were obviously improved using the adiabatic pulses. Improvement of the homogeneity of RF pulses was observed when B1 shim was used. These results suggest the usefulness of CSI using adiabatic pulses and B1 shim when small amount of metabolites of target is measured in MRS.
Department of Radiology, Tokyo Sekishinkai Shinryoku Neurosurgery.
Chie
C
Kikuchi
Mitsuhiro
M
Inoue
Kohei
K
Okawa
Jyunichi
J
Taguchi
Yoshifumi
Y
Hirota
Yohei
Y
Yanagiya
D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D011846:Radio Waves; D059629:Signal-To-Noise Ratio