Are perfusion parameters derived from bolus-tracking perfusion imaging immune to tracer recirculation?
Tracer recirculation does not impact estimation of CBF, CBV, or MTT. However, previous approaches used to remove recirculation effects may be beneficial when used to compensate for limited acquisition durations in which the passage of the bolus is not adequately captured.
The results indicate that large luteal cells are a major source of beta-endorphin in the porcine corpus luteum, where its release may be affected by gonadotropins (possibly LH) and TNFalpha.