How temperature and immersion liquid affect the relaxation properties in articular cartilage samples?

Motivation: Preclinical measurement series of articular cartilage samples are often time-consuming. Thus, knowledge about changes in relaxation properties of cartilage during measurements and depending on the sample handling is important. Goal(s): To study the effect of storage temperature and immersion liquid on the relaxation properties of articular cartilage. Approach: T1, T2, and adiabatic T1rho relaxation times were measured for 28 cartilage-bone samples at five timepoints and analyzed by linear regression. Results: T1 and adiabatic T1rho relaxation times increased over time, while T2 varied. Immersion in phosphate-buffered saline instead of signal-free perfluoropolyether increased the relaxation times in superficial cartilage. Impact: The study increases understanding on how the relaxation properties within ex vivo cartilage samples change over time. The results obtained here should be considered when planning future studies utilizing such samples.