Magnetic resonance surgery using heat waves produced with focussed ultrasound

A magnetic resonance (MR) surgery system that comprises:

• a) a pulsed heat means adapted for providing pulsed energy of an intensity and rate to an application point within a patient to establish a desired temperature distribution T(r,t) around the application point. The pulsed heat means comprising:
• 1. an ultrasonic transducer adapted for generating pulsed ultrasonic energy, and
• 2. focussing means adapted for focussing the pulsed ultrasonic energy at the application point to create the desired temperature distribution T(r,t) around the application point;
• b) MR compatible positioning means adapted for positioning the pulsed heat means and the application point to cause a selected tissue within the patient to have the desired temperature distribution T(r,t) where r is the radius from the application point and t is time;
• c) an MR imaging means adapted for creating fast scan MR images of the temperature distribution T(r,t) around the application point during surgery using a temperature sensitive pulse sequence;
• and
• d) display means adapted for interactively displaying the temperature sensitive images to an operator to allow the operator to control the temperature distribution T(r,t).

A method of performing heat surgery on a patient, as guided by a magnetic resonance (MR) imaging apparatus capable of producing temperature sensitive MR images, comprising the steps of:

• a) determining the position of a selected tissue to be destroyed in said patient with said MR imaging apparatus,
• b) applying pulsed heat of an amplitude Q at a pulse frequency f to an application point to create the desired temperature distribution T(r,t) around the application point where r is the radius from the application point and t is time by;
• 1. focussing ultrasonic waves on the application point, and
• 2. positioning the application point such that the temperature distribution T(r,t) would be positioned to destroy selected tissue within said patient without substantial injury to adjacent tissue;
• c) monitoring the temperature distribution T(r,t) with said MR imaging apparatus;
• and
• d) adjusting the frequency f, the amplitude Q and the location of the application point.