The disclosure provides echo planar imaging (EPI) based single-shot imaging techniques for acquiring spin-EPI (SEPI) and stimulated-EPI after a single RF excitation. In certain embodiments, the SEPI and STEPI acquired in a singleshot are used to compute a T1 map in realtime, which can be used for realtime monitoring of concentrations of paramagnetic-ion based contrast agent in dynamic contrast enhanced MRI. In certain embodiments, B1 field inhomogeneity correction is provided for the STEPI. In certain embodiments, a gradient-EPI (GEPI) is also acquired after the single RF excitation providing singleshot SEPI, GEPI and STEPI acquisition. In certain embodiments, the phase difference between the SEPI and GEPI is used to compute temperature-dependent chemical shift in a subject in realtime. The temperature-dependent chemical shift can be used to monitor temperature changes in the subject in realtime, for example, during a heat treatment to control the dosage of heat energy.