Ultrasound is currently used as a tool for providing 2D or 3D images for tumor localization and resection control. For the use in resection control the resection cavity is filled with saline to provide acoustic coupling between the ultrasound transducer and tissue. However, attenuation of acoustic waves is very low in saline compared to the brain and this difference in attenuation is the cause of artifacts that may severely degrade the ultrasound images. Such artifacts are seen as high-intensity signal at the resection cavity wall and beyond. The artificial signal enhancement can potentially mask small tumor remnants and is generally making the interpretation of images more difficult.