Fig. 2

Images of the setup and treatment planning. a T1 weighted magnetic resonance (MR) localizer (repetition time/echo time = 196/4 ms) for visualization of possible air bubbles within the ultrasound beam. The white line is the acoustic beam overlay. Dashed line is the plastic sheet on top of a water bath. Dotted line indicates the gel pad. Focal length ranges between 30–80 mm, acoustic window 48 mm in diameter. b T2 weighted MR images (repetition time/echo time = 3350/26 ms) to determine the tumor (T) and focus spots (dot within the tumor) using the trajectory planner software (Thermoguide, Image Guided Therapy, Pessac, France). The white box indicates the execution range (30 × 30 mm) of the high intensity focused ultrasound system. The mouse leg with tumor is visualized in a water bath. A small phantom (P) is positioned next to it for focus corrections. c Mouse positioned on its side, with the tumor inside a water bath and the nose of the mouse within a tube for anesthesia (An). The phantom cube (P) is position next to the mouse. Breathing rate (B) and rectal temperature are measured during treatment; an air-heater (H) is connected to the rectal thermometer to maintain the mouse core temperature