Relationship between Lumbar Vertebral Perfusion and Fat Marrow Content in Normal Subjects, Osteoporosis and Bone Metastases Using DCE-MRI and Fat-Water Separation

Dynamic contrast-enhanced MR imaging (DCE-MRI) has been proved to be highly correlated with microsphere blood flow measurement in bone marrow perfusion in animals and human of the lumbar vertebrae. Although DCE-MRI and MRS have shown potential in probing the bone marrow content and blood perfusion characteristics of the vertebral body in previous studies, all of these are a ROI (whole vertebral body) analysis, and therefore, loss of regional local information about bone marrow content and blood perfusion. Recently, three-point Dixon technical development has widened the field of utilization from a 3 point acquisition a water-only image and a fat-only image computed by pixel-by-pixel basis. Perfusion parameter map can also be calculated as pixel-by-pixel using pharmacokinetic model analysis for DCE-MRI data. The spatial analysis between regional perfusion and fat content of the vertebrae could be studied using DCE-MRI and three-point Dixon techniques. However, the mechanism of the regional enhancement in the vertebral body and the regional hemodynamic changes of the perfusion of vertebral body in relationship to the bone marrow content are not fully understood. The purpose of this research project has two main points. First, we attempt to build a MRI scanning and analysis to investigate the regional perfusion and bone marrow content of the vertebral body with use of DCE-MRI and 3-point Dixon technique in pixel-by-pixel analysis. Second, we attempt to explore the regional perfusion and bone marrow content of the vertebral body in patients with osteoporosis and bone metastases. We will recruit (1) 80 normal subjects (age 20~34, 10 women and 10 men; age 35~50, 10 women and 10 men; age 51~64, 10 women and 10 men; age age≧65, 10 women and 10 men); (2) 40 patients (age 51~64, 10 women and 10 men; age age≧65, 10 women and 10 men) of having osteoporotic compressive fractures; (3) 20 patients (10 women and 10 men; age≧55) of having vertebral metastases. With this proposal, we will establish a new model clarifying the relationship of blood perfusion and red/fat marrow of the vertebral body, and to investigate the microcirculation derived from arterial vessels entering the vertebral red/fat marrow. We believe that results of our study will be helpful in understanding the mechanism and hemodynamic change of normal population by age, osteoporosis and bone metastases, which can be of clinical impact in follow up after treatment.