Quantifying Cortical Bone Free Water Longitudinal Relaxation Time Employing Short-TE MRI Technique at 3T; A Feasibility Study

Aging is one of the most important factors affecting cortical bone quality, culminating in cortical bone thinning, increasing the number and size of the pores. As a consequence of these alterations the free water molecules mobility augments and their longitudinal relaxation time (T1) increases. Magnetic resonance imaging with its sensitivity to capture signal from hydrogen proton would be the best candidate to assess the bone quality during aging. By employing an appropriate pulse sequence with short TE (in the range of millisecond) which is capable of acquiring signal from hydrogen molecules of cortical bone pores before decaying, we extracted valuable information of the bone structure. In this feasibility study, five healthy volunteers (3f/2m) were undergone short TE MR imaging with dual-TR technique at 3T in order to calculate cortical bone free water longitudinal relaxation time. The obtained T1 values with the average of 589.32 ± 231.52 ms for cortical bone free water was in a good agreement with literature, and was promising in the sense that STE-MRI has the potential to be used in everyday clinics for cortical bone free water relaxometry.