Early detection of the onset of diseases are essential if we want to maintain good health. MRI technique provides a three-dimensional image of a microscopic lesion in an organ. Human body is made of 220 different tissues which interact to make an organ and several organs interact to make a human. As a part of medical record, taking MRI of each organ every year and comparing them with each other will identify the appearance of microscopic changes. For example, if you are diagnosed with Brain cancer today, you did not get the cancer yesterday. Abnormal changes are the result of accumulation of harmful mutations over the years predicting the onset of diseases. Once the brain tumor is confirmed, the patient dies within fourteen months. To save the life of the patient, the following three strategies are available and they are Surgery, Radiation and Chemotherapy. This article describes the Chemotherapeutic approach to treat cancers in general and brain cancer, Glioblastoma, in particular. Using rational approach, we designed AZQ (US Patent 4,146,622 & 4,233,215) to treat Glioblastomas. MRI Would identify appearance of microscopic lesions of Glioblastoma and help us start treatment with AZQ long before the disease is confirmed. Using similar rational approach of early diagnosis with MRI, we could design drugs to treat other diseases including cancers.