Temperature profile inside the simulated target lesion (BioGlue®). The temperature profile is shown for the simulated lesion during transthoracic high-intensity focused ultrasound insonation after in vivo flooding of the left lung of a pig. Temperature increases were monitored for each one-second treatment with HIFU irradiation. A section of 25 seconds of HIFU exposure following the ‘one second on/off’ scheme is demonstrated. The repeated HIFU insonation caused a temperature increase up to 54°C.