Comment: naming convention for gradient system transfer function and gradient system frequency response for magnetic resonance imaging encoding field characterization

The frequency response and transfer function of a system are closely related, but distinct concepts from a control system theory and signal processing perspective. Unfortunately, these concepts have been used inconsistently in the magnetic resonance imaging (MRI) literature for gradient characterization. This note highlights the differences, with the intention to establish a common naming convention, consistent with other engineering fields. This will facilitate communication between colleagues with a different research background, promoting knowledge transfer and potentially alleviate shortcomings that have resulted from the incorrect usage of the term "transfer function" for gradient characterization in the past.