A method (100) and system (1) for diagnosing reflux disease in an individual (3). The method (100) comprises: administering (110) an oral dose (17) of tracer in to the individual； capturing (120), with a single photon emission computed tomography (SPECT) scanner (5), data representative of multiple image frames (21) of the individual in areas of interest (23) that include the pharynx (25) and oesophagus (27), wherein the data representative of multiple image frames (21) are captured over time after administration of the oral dose； and determining (130) one or more trend(s) in tracer activity over time in the areas of interest (23) based on the data representative of multiple image frames (21), wherein the trend(s) in tracer activity over time is indicative of a reflux disease.
