The theme running through this thesis is quantitative MRI using 3D techniques, which allow isotropic coverage of whole organs and more accurate volumetric measurements and visualisation of small, complex structures. The use of contrast agents and the measurement of their concentration in vivo, as well as location and migration, is explored. In conclusion, this thesis describes the past, present and future of projects encompassing multidimensional quantitative MRI. The work has been drawn from small animal imaging, contrast agent development, novel sequences and applications to non-invasive follow-up in the clinical situation. The techniques aim to help in the move towards non-invasive and quantitative clinical diagnosis and monitoring.