Diagnostic ultrasound ( PDFDrive )

884 PART III Small Parts, Carotid Artery, and Peripheral Vessel Sonography
be continued posteriorly from the supraspinatus both in long
and short axis.
An alternate position of scanning the infraspinatus has been
described, in which the patient is asked to bring the arm forward
across the chest, resting the hand on the contralateral shoulder. 44,51
hese positions allow imaging of the infraspinatus tendon and
muscle. he probe is held in an oblique transverse orientation,
placed on the posterior shoulder to parallel the long axis of the
infraspinatus tendon, using the inferior border of the scapular
spine as a visual landmark (Fig. 24.11). In long axis the tendon
appears similar to the supraspinatus in morphology, although
having a more elongated tapered appearance at its insertion,
lacking the bird’s beak appearance seen at the supraspinatus
footprint. he probe is then rotated 90 degrees, to the short axis
of the infraspinatus, and the tendon and muscle are evaluated.
he normal muscle is hypoechoic and positioned below the
scapular spine in the infraspinatus fossa.
he teres minor tendon is also evaluated in this position and
is seen inserting at the posterior aspect of the greater tuberosity,
inferior to the infraspinatus insertion. he teres minor muscle
can be seen arising from the posterolateral scapula, inferior to
the infraspinatus muscle.
Also in this position, the posterior shoulder is seen, with
visualization of glenohumeral joint luid and limited views of
the posterior labrum and spinoglenoid notch. Scanning the
posterior shoulder with external rotation may aid visualization
of a glenohumeral efusion. 52
Rotator Cuff Musculature Evaluation
Using the scapular spine as a visual landmark, the supraspinatus
muscle in the supraspinatus fossa can be imaged by placing the
probe perpendicular to the scapular spine (Fig. 24.12). his
demonstrates the muscle in its short axis. he normal muscle
should be hypoechoic and convex in contour, and should ill the
FIG. 24.8 Long-Axis Biceps Tendon Image, With Shoulder in the
Modiied Crass Position. This is a good starting point for imaging the
supraspinatus tendon in long axis. Once the long head biceps tendon
is seen well in long axis (arrowheads), the probe can simply be moved
posteriorly to image the supraspinatus tendon.
FIG. 24.9 Overlap of Posterior Supraspinatus (Arrow) and Anterior
Infraspinatus Fibers (Arrowheads) Seen in Long Axis. See also Video
24.2.
A
B
FIG. 24.10 Rotator Cable. (A) The rotator cable (arrows) is visualized in short axis along the articular surface of the supraspinatus tendon,
when this tendon is imaged in long axis. (B) The rotator cable (arrows) is visualized as a linear structure in its long axis (arrows) along the articular
surface of the supraspinatus tendon, when this tendon is imaged in short axis. (Courtesy of Dr. Yoav Morag, Ann Arbor, MI.)