A musculoskeletal injection is an injection into joints (articular) or in soft tissue structures around joints (peri-articular) to relieve pain, reduce inflammation, and improve mobility. Diagnostic ultrasonography, often known as sonography or diagnostic medical sonography, is a type of imaging technique that use sound waves to create pictures of the internal organs and other structures in your body. The pictures can offer important information for diagnosing and determining the best course of treatment for a number of illnesses and ailments.