Melissa Ann Vogelsong1, Ernesto Staroswiecki2,
Brian A. Hargreaves, Eric Han3, Jill A. Fattor4, Anne
L. Friedlander5, Omer Shah6, Jacquie M. Beaubien7,
Garry E. Gold
1Radiology, Stanford University,
Stanford, CA, United States; 2Electrical Engineering, Stanford
University, Stanford, CA; 3GE Healthcare Global Applied Sciences
Laboratory, Menlo Park, CA; 4Stanford Center on Longevity, Stanford,
CA; 5VA Palo Alto Healthcare Center, Palo Alto, CA; 6Georgetown
University School of Medicine, Washington, DC; 7Psychology,
Stanford University, Stanford, CA
Several
imaging techniques are currently being investigated for use in visualizing
cartilage biochemistry. T2 mapping is thought to assess water content and
collagen structure while sodium imaging reflects proteoglycan content,
however precisely what affects T1ρ relaxation remains unclear. We imaged
9 knees of patients with osteoarthritis and measured T2 and T1ρ
relaxation times as well as sodium signal from corresponding ROIs. No
correlation was found between T1ρ relaxation and sodium signal, however
there was a moderate correlation between T1ρ and T2 relaxation. T1ρ
may therefore depend on a complex interaction of macromolecules rather than
proteoglycan content alone.