Correlation between water content and magnetization transfer ratio of the water component in bone marrow using gradient-echo imagings: normal case study.

Abstract

To determine the correlation between water content and magnetization transfer (MT) ratio of the water component in normal bone marrow using gradient-echo (GRE) magnetic resonance (MR) imaging. Three types of GRE sequence--using fat suppression, using a combination of MT and fat suppression techniques, and without MT or fat suppression--were performed in nine healthy subjects. The water content of bone marrow assessed with GRE imaging was compared with that assessed with MR spectroscopy in three cases. The correlation between water content and MT ratio was observed using GRE imaging in nine subjects. The water content as assessed by GRE imaging and by MR spectroscopy were closely correlated (P<0.005, r=0.932). An inverse correlation between water content and MT ratio was observed in normal bone marrow (P<0.03, r=-0.432), which suggests that the water component in bone marrow includes free water protons.