Improved off‐resonance phase behavior using a phase‐inverted adiabatic half‐passage pulse for 13C MRS in humans at 7 T

Abstract

In vivo 13C MRS at high field benefits from an improved SNR and spectral resolution especially when using surface coils in combination with adiabatic pulses, such as the adiabatic half‐passage (AHP) pulse for 13C excitation. However, the excitation profile of the AHP pulse is asymmetric relative to the carrier frequency, which could lead to asymmetric excitation of the spectral lines relative to the center of the spectrum. In this study, a pulse‐acquire sequence was designed for adiabatic 13C excitation with a symmetric bandwidth, utilizing a combination of two AHP pulses with inverted phases in alternate scans.