Tissue heating effect of pulsed Doppler ultrasound in the live fetal lamb brain.

A series of experiments in fetal lambs investigated the heating effects of pulsed Doppler ultrasound on fetal brain tissue. In dead lamb brain, tissue heating was observed at the skull bone-to-brain interface. Minimal or no temperature rise was found in the live lamb, suggesting that the intact circulation conducts away any potential heating. The choice of animal model and the state of the circulation influence the results obtained. This will of course have implications for clinical practice.