Fast 31P chemical shift imaging using SSFP methods

Abstract

Steady‐state free precession (SSFP) methods have been very successful due to their high signal and short imaging times. These properties make them good candidates for applications that intrinsically suffer from low signal such as low gamma nuclei imaging. A new chemical shift imaging (CSI) technique based on the SSFP signal formation has been implemented and applied to ³¹P. The signal properties of the SSFP CSI method have been evaluated and the steady‐state signal of ³¹P has been measured in human muscles. Due to the T₂ and T₁ signal dependence of SSFP, the steady‐state signal mainly consists of phosphocreatine (PCr). The technique allows fast CSI acquisitions with high SNR of the PCr signal. The SNR gain for PCr over a FLASH‐based CSI method is approx. 4–5. Fast in vivo CSI of human muscle with subcentimeter resolution and high SNR is demonstrated at 2 T. Magn Reson Med 48:633–639, 2002.