1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States; 2Department of Orthopedic Surgery, University of Minnesota, Minneapolis, Minnesota, United States; 3Department of Orthopedic Surgery, University of Minnesota, Minneapolis, MN, United States
SWIFT is an emerging technique that allows imaging of almost all biological objects including tissues having ultrashort T2 relaxation times (down to a few s). Besides nearly pure proton density weighted contrast, SWIFT can provide other types of contrasts, including T1, T2, T1rho, and T2rho by utilizing magnetization preparation blocks. In the present work we describe the theory and experimental setup to generate T1rho contrast in MP-SWIFT images and demonstrate T1rho quantification in osteochondral specimens. Additionally, the same concept of magnetization preparation is utilized to separate the different spin pools in an osteochondral specimen (fast relaxing spins and slow relaxing fatty or non-fat tissue).