Temperature dependence of T1 and T2* in ex vivo ovine Achilles tendons

Motivation: While the dependence of the relaxation parameters T1 and T2* on temperature has been studied in aqueous solutions and in some biological tissues, such observations for complex organized tissues including tendons have not been investigated previously. Goal(s): To measure how T1 and T2* change with temperature in Achilles tendon samples. Approach: T1 and T2* were continuously measured while fresh ex vivo Achilles tendon samples were placed in a heated environment and cooled down over several hours. Results: The change in T2* with temperature was nonlinear and much higher than that reported in the literature for other tissuesImpact: The change in T2* in Achilles tendons was 4.8+/-2.1%/°C, which is substantially higher than reported in other biological tissues and indicates that the theory of temperature dependence of MRI relaxation parameters may not apply to highly organized tissues like tendons.