An apparatus for cooling certain tissues in the vicinity of diseased or other tissue undergoing thermal treatment is disclosed. The present apparatus is configured and designed to have certain physical characteristics, e.g., certain acoustic and imaging responses. In some embodiments the present apparatus is compatible with magnetic resonance imaging (MRI) environments used in conjunction with the thermal treatment, or other imaging environments. In some embodiments the present apparatus is detectable by said MRI and is within the imaging field of view (FOV) but causes few or no imaging artifacts. Additionally, the present apparatus does not substantially interfere with the thermal treatment, e.g., ultrasonic therapy, which can proceed to heat the targeted volume of tissue while protective cooling of tissues near the diseased tissue by the present apparatus takes place.
