Quantification of Bone Marrow Water and Lipid Composition in OA and ACL-Injured Knees using 3D MR Spectroscopic Imaging

Spectroscopic Imaging Tufts, L; Shet Vishnudas, K; Majumdar, S; +Li, X University of California, Berkeley, CA, +University of California, San Francisco, CA [email protected] INTRODUCTION: Osteoarthritis is a multifactorial disease affecting not only cartilage but also other tissues in the joint including bone and bone marrow, and abnormal marrow lipid amount and composition may also contribute to OA. In both acutely injured knees and knees with OA, bone marrow edema-like lesions (BMELs; areas of high signal intensity in T2weighted, fat-saturated magnetic resonance (MR) images) are commonly present. BMELs have been correlated with cartilage degeneration and disease progression in OA. However, few studies investigated in vivo marrow composition in OA and acutely injured knees, and no study has been documented on the longitudinal marrow composition changes in such joints. The goals of this study were: 1) to quantify and compare bone marrow water and lipid composition between control, OA, and acutely anterior cruciate ligament (ACL)-injured knees within and outside the area of BMEL using 3D MR spectroscopic imaging (MRSI); 2) to quantify longitudinal changes in BMEL volume in OA and ACLinjured knees; and 3) to quantify longitudinal marrow composition changes within and outside the area of BMEL in these knees.