1) Cooperberg, P.L., Tsang, I., Truelove, L., et al.: Gray scale ultrasound in the evaluation of rheumatoid arthritis of the knee. Radiology, 126: 759-763, 1978.
2) De Flaviis, L., Scaglione, P., Nessi, R., et al.: Ultrasonography of the hand in rheumatoid arthritis. Acta Radiol., 29: 457-460, 1988.
3) Fornage, B.D., Schernberg, F.Z., Rifkin, M.D.: Ultrasound examination of the hand. Radiology, 155 : 785-788, 1985.
4) Fornage, B.D.: The hypoechoic normal tendon, a pitfall, J. Ultrasound Med., 6: 19-22, 1987.
5) Fornage, B.D.: Soft-tissue changes in the hand in rheumatoid arthitis: evaluation with US. Radiology, 173: 735-737, 1989.