Two-dimensional relaxation measurements have similar advantages to two-dimensional spectroscopy measurements. Advantages include better resolution and more information about interactions and exchange among spin systems having different relaxation rates. Two-dimensional relaxation measurements have been used for decades , but early applications were hindered by challenges with data analysis. Their use accelerated following the publication of a rapid 2D Inverse Laplace Transform method , and they are now widely applied. An incomplete list of a few of the many current research topics related to two-dimensional relaxation measurements include development of processing algorithms , classification of food products , porous media characterization , and investigations of biomaterials like cartilage . There does not appear to be widespread agreement on the best methods for processing or for parameterizing the information content of 2D measurements.