MR scanner independent 3D B1 eld mapping of magnetic resonance spectroscopy RF coils using an automated measurement system

Knowledge about the magnetic eld distribution in radio frequency coils is important for both magnetic resonance imaging and magnetic resonance spectroscopy. The information about the eld's distribution is used to obtain correct excitation pulse ip angles, as well as to perform signal strength corrections. Another use is also accelerating imaging and spectroscopic examinations, where accurate de nition of the B1 eld is essential to perform proper image and/or spectrum reconstruction. We developed a method for measurement of the B1 /B + 1 elds as an alternative approach to B1 /B + 1 elds assessment in MR scanner. Our setup incorporates an industrial coordinate table controlled by a PC-based program, search coils, a two port vector network analyzer and an analog-to-digital (A/D) card. It is possible to measure in various liquid media (for example in saline solution) to mimic di erent shapes and dielectric properties of the human body.