Systems and methods for measuring macromolecular proton fraction in a subject are provided. A nuclear magnetic resonance apparatus applies a magnetic field to a body region on the subject, and radiofrequency modes are applied to the body region as well. Each radiofrequency mode delivers a plurality of radiofrequency pulses separated by time delays, wherein at least one of the radiofrequency modes causes suppression of signal components from an unwanted tissue, and at least one of the radiofrequency modes causes magnetization exchange between water and macromolecules in tissues in the body region. Amplitudes corresponding to magnetic signals received from the body region are measured and macromolecular proton fraction based on the amplitudes can be calculated.