Figure 19. Artifactual reduction in tendon echogenicity attributable to tendon anisotropy. Coronal (longitudinal) US image shows hypoechoic appearance of the distal rotator cuff tendon that extends to the insertion site (arrows). Compare this with the appearance of the rotator cuff in Figures 3b, 4, 6, and 21d. The examiner must make a conscious effort to continually reorient the US probe so that it is perpendicular to the direction of cuff fibers; otherwise, anisotropy may be mistaken for a cuff tear.