The invention is an apparatus and method for treatments and targeted drug delivery into a living patient, particularly but not exclusively using magnetic resonance (MR) imaging. The apparatus and method are useful in delivery to all types of living tissue and uses MR Imaging to track the location of drug delivery and estimating the rate of drug delivery. An MR-visible drug delivery device positioned at a target site (e.g., intracranial delivery) delivers a diagnostic or therapeutic drug solution into the tissue (e.g., the brain). The spinal distribution kinetics of the injected or infused drug agent are monitored quantitatively and non-invasively using water proton directional diffusion MR imaging to establish the efficacy of drug delivery at a targeted location.