Diagnostic ultrasound ( PDFDrive )

882 PART III Small Parts, Carotid Artery, and Peripheral Vessel Sonography
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FIG. 24.5 Subscapularis Tendon. (A) Long-axis probe position. From the long head biceps tendon (LHBT) starting position, the patient now
externally rotates the elbow, keeping the elbow tight to the body with the palm up. This position elongates the subscapularis tendon and rotates
the tendon out from under the coracoid process, allowing visualization. The probe is placed across from the coracoid process. Note that the probe
position is similar for imaging the LHBT in short axis, but the patient’s position is different. (B) Long-axis image of subscapularis tendon (arrowheads).
(C) Short-axis probe position. From the long-axis starting position, the probe is simply turned 90 degrees to image the subscapularis in short axis,
with the patient remaining in the same position. Note that the probe position is similar to the LHBT long-axis probe position, but the patient’s
position is different. (D) Short-axis image of subscapularis tendon (arrowheads). See also Video 24.1.
anterior to the tendon, with the biceps tendon coursing through
the interval, also in short axis, stabilized by the coracohumeral
ligament and superior glenohumeral ligament.
As with all tendons, the supraspinatus should be scanned
through its entirety from anterior to posterior in long axis and
medial to lateral in short axis. When the posterior ibers of the
supraspinatus tendon are reached, the more posteriorly oriented
ibers of the infraspinatus tendon are routinely encountered; this
is a helpful landmark to ensure the entire supraspinatus tendon
has been studied. It is important to note that as the transducer
is moved posteriorly, the greater tuberosity changes shape, from
ledgelike to lat. his area of transition is where the anterior
infraspinatus ibers overlap the posterior supraspinatus ibers.
A discrete overlap of ibers can be visualized at this juncture
(Fig. 24.9, Video 24.2). Continuing posteriorly from this overlap,
the infraspinatus ibers can be evaluated in their entirety, looking
for the similar normal ibrillar pattern in the long axis, and the
echogenic appearance in the short axis.
he rotator cable is a thin ibrous band contiguous with the
coracohumeral ligament that passes along the deep surface of
the supraspinatus and infraspinatus tendons. 47 his bandlike
structure is oriented perpendicular to the long axis of the rotator
cuf, running in an anterior to posterior direction, and is felt to
have a biomechanical role in stress distribution, likened to the
cable of a suspension bridge. 48 It can be visualized consistently
with ultrasound, seen in its short axis where it appears elliptical,
when scanning the long axis of the supraspinatus and infraspinatus
(Fig. 24.10). It is located about 1 cm (average 9 mm, range
4-15 mm 47 ) medial to the rotator cuf insertion at the greater
tuberosity.
Dynamic assessment for subacromial impingement of the
supraspinatus can now be performed. he patient’s arm rests in
a neutral position at his or her side, and the probe is positioned
in a coronal plane, with the acromion at the medial aspect of
the ield of view, and the greater tuberosity laterally. he patient
then abducts the arm slowly, and the motion of the supraspinatus