Ultrasound is a non-invasive method of imaging of internal structures which includes the abdomen, thorax (heart), etc. Ultrasound can be used to guide biopsies and centesis needles for retrieval of small volume samples or close to vital structures, such as mediastinal masses. Ultrasound can be used in unanesthetized and non-sedated animals, reducing the need for anaesthesia in high-risk patients (geriatric, pediatric, organ compromised). Many pet owners want the most advanced diagnostics available for their pet, while other owners want to avoid the perceived risk of surgery.