This study is to assess the addition of 3D ultrasound guidance during standard care ablation or biopsies of liver or kidney tumours. 3D ultrasound only differs from conventional 2D ultrasound in that the ultrasound transducer is mounted on a special assembly that moves the transducer in precise, stepped movements while a succession of 2D images are collected by the computer. Special software written specifically for 3D ultrasound precisely aligns these 2D images into a 3-demensional volume , allowing area in question to be viewed in many different planes. 3D ultrasound is a safe, fast, non-invasive imaging procedure. Ultrasound images will be checked against the pre- and post- procedure CT images to make sure the tumours were completely removed or properly targeted during biopsy.