Technique and diagnostic value of musculoskeletal ultrasonography in rheumatology Part 1: Ultrasonography of the knee

Within the last few years, ultrasonography (US) of joints has attained a fi rm position for the diagnosis of joint diseases. Degenerative as well as in flammatory changes can be recognized using this method. With new, higher re solution techniques even bone surfaces and tendon textures can be-visualize d in greater detail. The advantages of sonography are general availability and low costs. When used properly, as a non-invasive procedure US has no de trimental effects on patients. The disadvantages of this technique result f rom its physical limitations, such as high reflection of US on bone and the negative correlation between resolution and penetration which makes US ima ging difficult in deeper regions. The current technical development of prob es and imaging processing, however, promises better deep structure imaging in the future. The quality of ultrasound examination always depends on the technical equipment, as well as on the patients' individual tissue constitu tion and the experience of the physician. It is possible to avoid misinterp retation and to increase the diagnostic value of US by using a standardized technique and professional knowledge of the specific aspects of the method . The significance of qualified education and sufficient training of sonogr aphers is to be stressed. The aim of this article is to deliver a basic contribution to the standardi zation and quality assurance of joint US and to indicate the value of this method. In addition to the overview the authors propose guidelines for perf ormance and interpretation of joint US. Due to the major significance of th e knee joint in rheumatology it was decided to begin the work in this area.