Improving the low signal-to-noise ratio (SNR) inherent to emerging MRI methods such as fluorine MRI is challenging. To enhance sensitivity, SNR-efficient pulse sequences such as RARE and cryogenically-cooled surface RF coils (CRP) are used. Transceive surface RF coils show variation in the excitation field (B1+), impairing quantification. To compensate, previous studies have used an analytical signal intensity equation to perform a retrospective B1+-correction. However, this is unfeasible for RARE due to the absence of such an equation. To overcome this challenge, we propose and validate a numerical method using experimental data acquired with a volume resonator (reference) and a 1H-CRP.