Magnetic resonance imaging (MRI) is a cutting-edge imaging technique that has been widely and successfully used in clinical diagnoses and biological researches. However, challenges usually arise when using conventional MRI pulse sequences to image short T2 tissues or materials, such as cortical bone, teeth, tendon, iron oxide nanoparticles, and etc., since these materials are associated with fast-decaying MR signals. Meanwhile, there exists an enormous demand to overcome these challenges to improve detection and quantification of short T2 materials. For example, improvement of detection specificity of cells labeled by iron oxide nanoparticles is crucial for researchers to in vivo track cells and to understand the behaviors of cells. Another example is that quantification of water components in cortical bone is of critical importance to understand and diagnose bone diseases, such as osteoporosis. The objectives of this dissertation are to propose novel approaches of MRI to qualitatively and quantitatively study the short T2 materials, with main focus placed on iron oxide nanoparticles and cortical bone.