Tendons appear on ultrasound as densely packed parallel hyperechoic fibrils with a characteristic fibrillar echotexture — best seen when the beam is perpendicular to the tendon long axis. Rotating the transducer away from perpendicular produces anisotropy — a drop in echogenicity that mimics tendon pathology and must be recognized as a normal artifact. Tendon pathology includes tendinosis (fusiform swelling, loss of fibrillar pattern, hypoechoic change), partial tear (focal discontinuity), and complete tear (gap with retraction of tendon ends).