ABSTRACT
The first clinical report (1) that combined magnetic resonance imaging (MRI) guidance
and temperature monitoring with focused ultrasound surgery demonstrated feasibility and
showed that high focal temperatures (60-90˚C) induced by ultrasound can be monitored
by magnetic resonance (MR) thermometry. Although the single focused ultrasound
systems used in the first clinical studies (1-4) were integrated with the MRI scanner, they
were limited due to the small focal spot volume and the range of the mechanical motion
of the transducer in the depth direction. The early clinical systems were also limited in
their ability to use the MR thermometry. They could visualize single temperature maps,
but they did not track the thermal dose distribution (1).