Systems and methods for magnetic resonance imaging (“MRI”) of multiple different nuclear spin species using the same radio frequency (“RF”) coil are described. Generally, multiple different nuclear spin species are imaged using the same RF coil by using an MRI system whose magnetic field can be rapidly ramped between a number of different, and arbitrary, magnetic field strengths. The magnetic field of this MRI system can be ramped to different values in reasonable amounts of time (e.g., in a time frame that is feasible within an imaging study).