Ultrasound gel is water-based. It is used for all types of ultrasound exams, including obstetric, vascular and cardiac.
 
Ultrasound gel. A premium, thick ultrasound gel with proven incredibly high transmission results.
Applying a gel to the skin during an ultrasound procedure allows the transducer to pass over the skin more easily so that it makes better contact with the body.
 
Water soluble and hypoallergenic.