A magnetic resonance imaging system (1) includes a data acquisition system (11) with a main magnet (12) with an imaging volume. A gradient system (G) generates field gradients (Gx), (Gy) and (Gz). An RF excitation system (10) generates radio-frequency (RF) excitation pulses. In a receiving mode, an RF coil senses a response, for example in the form of free induction decay signals, including echo signals. An image processor (26) is arranged to extract thermometry data and longitudinal relaxation time data from the acquired MR signals and to forward corresponding reconstructed images to a display unit (28).