Methods for assessing steatosis and fibrosis in a patient's liver include (i) measuring a diffusion-weighted relaxometry signal of the liver, or portion thereof; and determining a fibrosis content of the liver or portion thereof based on the measured diffusion-weighted relaxometry signal, or (ii) measuring a relaxometry signal of the liver, or portion thereof; and determining a fat content of the liver or portion thereof based on the measured relaxometry signal. A system for such non-invasive sensing includes a static magnetic field source; RF transmitter coils connected to a pulse sequence generator; RF receiver coils configured to detect a magnetic field generated within liver tissues; and a signal acquisition and processor system configured to acquire signals from the RF receiver coils and perform a relaxation time (T2) relaxometry measurement, wherein the RF transmitter coils and pulse sequence generator are configured to apply a varying magnetic field to the liver tissues.