An apparatus for measuring liver fat content and/or iron content non-invasively in vivo using unilateral NMR technology is disclosed. The apparatus comprises a unilateral NMR probe positioned against or in the proximity of the body. The probe generates static and RF magnetic fields to measure NMR signals at selected depths into the body. The apparatus further comprises a unilateral magnet and a unilateral antenna placed between a magnet and the body or around the magnet. The unilateral antenna is used to attain NMR signals. The measurement of NMR signals at a single position with a single frequency determines fat content on a specific volume inside the liver. The measurement of NMR signals at a single position with two or more frequencies determines iron content on a specific volume inside the liver.
