Diagnostic ultrasound ( PDFDrive )

880 PART III Small Parts, Carotid Artery, and Peripheral Vessel Sonography
Acromion
Acromioclavicular
joint
Coracoid
process
Clavicle
Subscapularis
Supraspinatus
Lesser tuberosity
Greater tuberosity
Bicipital tendon
sheath
Subscapularis
tendon
Bicipital tendon
Biceps muscle
(long head)
Glenohumeral
joint
Scapula
FIG. 24.3 Illustration of the Long Head Biceps Tendon in the Rotator Interval and in the Bicipital Groove.
TABLE 24.1 Routine Shoulder
Ultrasound Protocol
Long head of biceps
tendon
Subscapularis tendon
Supraspinatus tendon
Infraspinatus tendon
Teres minor tendon
Supraspinatus and
infraspinatus
muscles
Posterior shoulder
Acromioclavicular joint
Long and short-axis static images
Long and short-axis static images
Dynamic evaluation for
subcoracoid impingement
Long and short-axis static images
Dynamic evaluation for
subacromial impingement
Long and short-axis static images
Long and short-axis static images
Sagittal images—panorama if
possible
Axial plane image
Coronal plane image
that the sonographer’s arm can be held in a natural, ergonomic
position. If a patient is wheelchair-bound, it is helpful if possible
to temporarily remove the backrest. If the patient cannot sit
upright, more limited scanning is possible with the patient lying
supine, with the afected shoulder at the edge of the bed. A
high-frequency 12- to 15-MHz linear array transducer is used
to permit high-resolution scanning. Occasionally, in larger
patients, a lower-frequency probe (9 MHz) may be needed to
achieve tissue penetration to the required depth, but this incurs
a reduction in resolution.
When scanning any tendon, care should be taken to maintain
an angle of close to 90 degrees between the probe and the tendon
of interest to avoid artifactual hypoechogenicity due to anisotropy.
his is discussed in more detail later in the chapter.
Biceps Tendon Evaluation
Biceps tendon evaluation is best performed with the arm in a
neutral position, resting the forearm on the patient’s ipsilateral
thigh, with elbow lexed and the palm up (Fig. 24.4). In this
position, the biceps tendon is seen anteriorly. 45 he tendon can
be imaged in its short axis within the bicipital groove by holding
the probe transversely with respect to the upper arm and following
the course of the tendon inferiorly where it passes deep to the
pectoralis major tendon insertion on the humerus. In short axis,
the tendon appears as a homogeneous, echogenic, round or ovoid
structure that may be accompanied by a trace of luid within its
tendon sheath. he normal biceps tendon is 2 to 4 mm thick. 36
he tendon can be followed superiorly and medially into the
rotator interval, by angling the probe more obliquely to remain
orthogonal to its short axis. Finally, the probe can be rotated 90
degrees to view the tendon in its long axis where it should appear
smooth and ibrillar.
Subscapularis Tendon Evaluation
he subscapularis is scanned with the patient’s arm at the side,
in external rotation with the palm facing up 44 (Fig. 24.5). he
tendon should be evaluated in long axis, with the probe aligned
with the subscapularis tendon, and in short axis, with the probe
held perpendicular to the subscapularis tendon. he coracoid
process of the scapula, medial to the subscapularis and palpable
in many patients, is a useful anatomic landmark when locating
the subscapularis tendon. he tendon ibers can be seen emanating
from the broad multipennate muscle belly. he normal hypoechoic
muscle should not be mistaken for luid. In this position the
patient’s arm can be rotated from external rotation to neutral
position, while observing the passage of the tendon ibers deep
to the coracoid process to assess for subcoracoid impingement
(Video 24.1). his dynamic maneuver is also useful to assess for
long head biceps tendon subluxation from the bicipital groove.