Osteoporosis is a disease of weak bone and increased fracture risk caused by low bone mass and microarchitectural deterioration of bone tissue. The standard-of-care test used to diagnose osteoporosis, dual-energy x-ray absorptiometry (DXA) estimation of areal bone mineral density (BMD), has limitations as a tool to identify patients at risk for fracture and as a tool to monitor therapy response. Magnetic resonance imaging (MRI) assessment of bone structure and microarchitecture has been proposed as another method to assess bone quality and fracture risk in vivo. MRI is advantageous because it is noninvasive, does not require ionizing radiation and can evaluate both cortical and trabecular bone. In this review article, we summarize and discuss research progress on MRI of bone structure and microarchitecture over the last decade, focusing on in vivo translational studies. Single center, in vivo studies have provided some evidence for the added value of MRI as a biomarker of fracture risk or treatment response. Larger, prospective, multicenter studies are needed in the future to validate the results of these initial translational studies.

Moreover, he assures me that it's understandable to make mistakes and encourages me to think boldly. His attitude and words always inspire me to do research in a consistent, peaceful, and innovative way. Also, I'd like to give my special thanks to Professor Gregory Chang from NYU for providing the data. Whenever I had questions, he would reply in no time, clear my doubts, and make it possible that my research went on smoothly. I am grateful for all the help I got from my excellent labmates, Cheng Chen, Dakai Jin, Syed Ahmed Nadeem, and Indranil Guha, on my research. And I am also thankful that the incredible faculty and staff I have met at the University of Iowa make my life easier.