The effect of freeze-thawing on magnetic resonance imaging T2* of freshly harvested bovine patellar tendon.

BACKGROUND Analysis of fresh specimens in research studies is ideal; however, it is often necessary to freeze samples for evaluation at a later time. Limited evaluation of the effect of freeze-thawing of tendon tissue samples on inherent magnetic resonance imaging (MRI) parameters, such as ultrashort echo time (UTE) T2* values, have been performed to date. METHODS This study performed UTE MRI on 14 bovine patellar tendons at harvest and after four consecutive freeze-thaw cycles. RESULTS Results demonstrated a small but significant reduction (12%) in tendon T2* values after the first freeze thaw cycle, but not after successive cycles. Tendons from juvenile animals with open physis had a significant reduction of T2* following a single freeze thaw cycle, P<0.0001. CONCLUSIONS The results of this study emphasize the importance of using uniform tendon storage protocols when using UTE MRI in preclinical models.