The physical basis of using MRI for cancer detection

MRI (Magnetic Resonance imaging) is a very important technique in bio-medical physics. The MRI device has become a must-have diagnostic tool in most hospitals and large clinics today. Thus, there is a strong interest to understand how NMR measurements can differentiate cancer cells from normal cells. One key finding in the development of the MRI techniques was that, the contrast of MRI image was found to be based on difference in nuclear relaxation times rather than concentration difference of cellular water. At present, there is still a challenge to understand the mechanisms behind relaxation time changes of water protons during cancer development. In this talk, I will review the history of MRI development and discuss the possible physical mechanism behind the relaxation time changes between normal cells and cancer cells.