. . . . . . . "The cavity may be filled with an aqueous or non-aqueous coupling medium including, but not limited to, water, saline, alcohols including ethanol and isopropanol (in a concentration range of 10 to 100% in aqueous solution), surfactants such as Triton X-100 or Sodium Dodecyl Sulfate (preferably in a concentration range of between 0.001 and 10% in aqueous solution), DMSO (preferably in a concentratio" .