In Ultrasound to gain higher tissue temperatures should we use Longer duration, Lower frequency and Lower intensity settings?

To achieve higher tissue temperatures (thermal effects) using Ultrasound treatment, applications should be of longer duration, in continuous mode and of higher intensity settings.

Frequency typically determines the depth of tissue targeted. Lower frequency values e.g. 1MHz mean that deeper tissues are being targeted –  as opposed to the treatment of more superficial tissues using higher frequency values e.g. 3MHz. In other words, treatments using higher frequency settings can still achieve significant thermal effects if the treatment time is long enough and if both continuous mode and high intensities are selected.