Development of Magnetic Resonance-based Functional Imaging: The Past, the Present, and the Future

The term "theranostics" is a compound word combining "therapeutics" and "diagnostics". Discovery of the X-ray made an extraordinary contribution to the field of medical science. Development of computer science after World War II has been absolutely imperative for the development of medical imaging technology to date. The invention of X-ray computed tomography (CT) has revolutionized medical image diagnostic systems. Several functional imaging modalities emerged not only in the radiological field but also in magnetic resonance and ultrasonic fields. The fusion of three digital imaging techniques, MR Redox imaging, electron paramagnetic resonance (EPR) oxygen mapping, and hyperpolarized (13)C MRI techniques in the magnetic resonance field, contribute to the newly-termed theranostics. Future development of a suitable contrast agent for each imaging modality will be a key for the success of theranositics.