2. USG EQUIPMENT: PROBES
• A linear probe is most often utilized in
musculoskeletal medicine
• It allows for more accurate evaluation of structures
close to the skin surface
• 8–18 mhz higher frequency allows them to obtain
greater resolution of near-field structures
• The sacrifice of depth and penetration
3. USG EQUIPMENT: PROBES
• A curvilinear probe by comparison allows great
resolution of deeper structures
• When greater depth of visualization is required, a
curvilinear probe is preferred
• Common clinical indications in musculoskeletal
ultrasound for utilization of a curvilinear probe
include ultrasound of the hip, spine, and
glenohumeral joint
4. USG EQUIPMENT: PROBES
• Ultrasound of small structures, including the hands
and feet, may be best visualized with a small-footprint
probe such a “hockey stick” probe
5.
6. ULTRASOUND TERMINOLOGY
• Hyperechoic (HYPER):
• High reflectivity displayed as a bright or light signal
• Bone (radial head (RH)) and tendon are examples of
hyperechoic objects
• Isoechoic (ISO)
• When two adjacent objects are of equal echogenicity
(common extensor tendon (CET) and fascia).
7. ULTRASOUND TERMINOLOGY
• Hypoechoic (hypo)
• Low reflectivity displayed as a darker area. Muscle
fiber bundles are an example of hypoechoic
structures (muscle fibers)
• Anechoic (AN)
• Absence of ultrasound reflectivity/signal displayed
as a black area. Fluid and articular cartilage are
commonly displayed as anechoic..
8.
9. ULTRASOUND IMAGING ARTIFACTS
• Anisotropy
• Anisotropy is the property of tendons, nerves, and
muscle to display a different appearance depending
upon the angle the ultrasound signal is directed
(insonation)
• When an ultrasound sound beam is at an angle less
than 85°, the majority of the sound waves will not
reflect back to the transducer.
10. ULTRASOUND IMAGING ARTIFACTS
• This results in a normally hyperechoic (bright)
structure appearing hypoechoic (dark)
• Tendons exhibit the greatest amount of anisotropy,
and the loss of the normal tendon fibrillar structure
may be misinterpreted as a tear or area of
tendinosis
• The operator can correct the anisotropy by angling
the probe sound waves perpendicular to the
structure
11.
12. ACOUSTIC SHADOWING
• Acoustic shadowing is the attenuation
of sound waves due to very dense
substance that reflects nearly all the
sound waves.
• This results in a lack of visualization
deep to the structure.
• Commonly, this can occur from bone,
foreign bodies, and
intratendinous/muscular
calcifications.
13. ACOUSTIC ENHANCEMENT
• Acoustic enhancement
results from sound waves
passing through anechoic
(black-appearing)
structures (fluid)
• The structures deep to the
fluid then appear more
echogenic than the same
tissue on either side of the
fluid
14. REVERBERATION ARTIFACT
• Reverberation artifact results from sound waves
reflecting back and forth between the surface of the
transducer and a highly echogenic structure
• The resulting image is one of evenly spaced lines of
the structure at increasing depths.
• Needle guidance is a common scenario in which
reverberation artifact can occur when the needle is
near perpendicular to the probe
15.
16. REFRACTION ARTIFACT
• Refraction artifact is also known as
edge shadowing and occurs distal to
the edges of curvilinear structures
• Sound waves impacting a curved
surface are refracted/bent from their
original direction, resulting in falsely
hypoechoic edge shadowing distally
18. MUSCLE
• Composed of multiple fascicles each embedded in
perimysium, a thin layer of connective tissue and fat
• Ultrasound pattern of muscle is typically feathery, or
pennate, with fiber orientation usually directed along
the long axis of the muscle
• In the short-axis view, the muscle fibers demonstrate a
speckled appearance
19. MUSCLE
• Fibers typically converge to the myotendinous
junction and the muscle tapers in diameter at this
point
• A thin layer of fascia surrounds the muscle unit,
separating it from adjacent muscles and
subcutaneous fat
• Muscle is usually overall hypoechoic, with more
echogenic internal linear interfaces generated by the
perimysium
20.
21. MUSCLE INJURY
• Grade I injury I
• A minor strain and is depicted on ultrasound as just
minimal fiber elongation and hypoechogenicity, but
without detectible discontinuity.
• Ultrasound is less sensitive than mri to these minor
grades of injury
• Treated conservatively
22. MUSCLE INJURY
• Grade II injury
• Partial tear
• Fiber discontinuity is seen, with a focal anechoic or
hypoechoic gap, usually filled by more echogenic
hematoma
• Gentle probe pressure can demonstrate muscle
fibers floating freely within fluid and hematoma,
referred to as the “bell-clapper” sign
23. MUSCLE INJURY
• Grade III injury, or complete tear
• Muscle is completely interrupted with retraction of
the muscle ends
• An interposed gap, which should be measured.
• A large hematoma is expected in association with
a complete tear
24.
25.
26. TENNIS LEG
• Medial gastrocnemius muscle tears away from the
aponeurosis with the underlying soleus muscle
• Fluid and hematoma may dissect along the
aponeurotic plane with retraction of the medial
gastrocnemius
• Usually occurs during forceful plantar flexion during
sports, for example, in a forceful lunge in tennis
• Injury may be accompanied by a plantaris tendon tear.
27.
28. MYOFASCIAL DEFECTS
• In this injury a defect in the muscular fascia allows
herniation of muscle fibers, leading to a palpable and
often painful mass
• May have associated neuropathy resulting from
compression of adjacent nerves
29. MYOFASCIAL DEFECTS
• Mass may be more apparent to the patient during
certain movements and activities that lead to muscle
contraction
• On ultrasound imaging, focused evaluation of the
region of concern reveals focal bulging of muscle
fibers through the otherwise smooth fascia.
30.
31. MUSCLE ATROPHY
• Occur in response to
denervation or chronic injury
• Characterized on ultrasound as
a decrease in muscle bulk and
a relative increase in
echogenicity, reflecting
replacement of muscle fibers
with fatty tissue
32. MUSCLE ATROPHY
• Comparison with adjacent muscles or the
contralateral side can assist in subtle cases.
• As a result of increased echogenicity, the visibility of
the central tendon at the myotendinous junction is
diminished, and there is a loss of normal pennate
pattern
34. TENDONS
• Normal tendons are composed of longitudinally oriented
bundles of collagen
• Fibers, which give a highly organized echogenic linear fibrillar
or striated pattern on ultrasound when viewed in long axis
• In short-axis view, normal tendons are usually smooth and
ovoid in outline, with a homogenous stippled appearance,
representing the tendon fibers viewed en face
35.
36. TENDONS
• Flexor and extensor
tendons of the hand and
wrist, are invested in a
synovial lined sheath,
• Achilles tendon, are
enveloped in a layer of
loose areolar tissue called
a paratenon.
37. TENDINOSIS
• Tendinosis consists of tendon
expansion and loss of clear
demarcation of collagen
bundles, with increased
mucoid ground substance
among collagen bundles
• There is non inflammatory
fibroblastic and
myofibroblastic cellular
proliferation
38. TENDINOSIS
• On ultrasound, tendinosis appears as
an area of hypoechogenicity, without
discontinuity, frequently associated
with varying degrees of tendon
thickening
• Dystrophic calcification, and even
ossification, can be seen within
affected tendons
• An additional characteristic feature is
the development of neovascularization
40. TENDON TEARS
• Partial tears:
• Transversely oriented (parallel to the
short axis of the tendon)
• Longitudinally oriented (parallel to the
long axis of the tendon, also referred
to as a “longitudinal split tear”)
41. COMPLETE TEAR
• Tendon fibers are entirely discontinuous and some degree of tendon
retraction may occur because of now-unopposed muscle contraction
• The extent of retraction
• In an acute tear, there may be complex fluid and hematoma within and
about the tear site
42. TENOSYNOVITIS
• Inflammation of the tendon sheath
• May occur as an overuse phenomenon or as a
result of an inflammatory condition, such as
rheumatoid arthritis
• On USG
• An increase of fluid volume around a
tendon within its sheath
• Tendon sheath can thicken and demonstrate
hypervascularity on doppler evaluation
44. LIGAMENTS
• Excellent technique for the evaluation of ligamentous
injuries, with some advantages over MRI
• Normal ligaments consist of interweaved bundles of
collagen, extending between bones, usually restricting
joint movements to prevent pathologic motion
• Ligament injury leads to pain and instability
• Normal ligaments are linear bandlike structures and
appear hyperechoic and fibrillar
49. STENER LESION
• A Stener lesion occurs when a thumb
metacarpal phalangeal ulnar collateral
ligament tear entraps the adductor
aponeurosis such that the ligament lies
superficial to the aponeurosis
• The appearance of a Stener lesion on
ultrasound is of retracted hypoechoic
ligament fibers displaced over the linear
aponeurosis, giving rise to the “yo-yo on
a string” appearance
51. NERVES
• Nerves have a characteristic honeycomb morphology
on ultrasound when imaged in short axis
• They demonstrate an internal striated pattern,
somewhat similar to tendons but with a coarser
pattern referred to as a “fascicular pattern”
• This pattern consists of alternating internal
hypoechoic and hyperechoic linear components
52. NERVES
• The hypoechoic components represent
fascicles or groups of fascicles, whereas
the hyperechoic parts correspond with the
epineurium
• The epineurium consists of connective
tissue that surrounds nerve fascicles,
composed of collagenous and adipose
components, with small blood vessels and
lymphatics
53. NERVES
• On short-axis view, peripheral nerves appear
ovoid or round and have punctate internal
hypoechoic fat representing nerve fascicles
within the echogenic epineurium
• Dynamic maneuvers including flexion and
extension of the imaged region should show
no substantial motion of a peripheral nerve,
as distinct from tendons.
54. ASSESSMENT OF NERVES
• Performed primarily in the short-axis plane
• The nerve is evaluated at a known anatomic location
and followed proximally and distally as needed
• Longitudinal scanning is helpful for providing an
overview and illustrating relative caliber changes of
peripheral nerves detected on transverse imaging
55. CARPAL TUNNEL SYNDROME
• Compression and flattening of the nerve
occurs within the carpal tunnel, at the
palmar aspect of the wrist
• The nerve is typically swollen and expanded
just proximal to the carpal tunnel
• Sonographic diagnosis of carpal tunnel
syndrome is made by measuring the cross-
sectional area of the median nerve at the
level of the pronator quadratus and
comparing this to the cross-sectional area
of the median nerve in the carpal tunnel at
56. CARPAL TUNNEL SYNDROME
• A difference of more than 2 mm2
between the two measurements is
highly associated with carpal tunnel
• Variable cut-off values for the
diagnosis of carpal tunnel syndrome
based on single cross-sectional
measurements of the median nerve in
the carpal tunnel : 9- to 11-mm2
range
• Bowing and thickening of the
overlying flexor retinaculum can also
57.
58. ULNAR NERVE SUBLUXATION
• The ulnar nerve normally passes through this fibro-
osseous tunnel at the posterior aspect of the humerus
and is stabilized by an overlying retinaculum
• The retinaculum normally passes between the
olecranon and the medial epicondyle of the humerus
59. ULNAR NERVE SUBLUXATION
• Developmental or
posttraumatic deficiency of
this retinaculum can allow the
ulnar nerve to dynamically
subluxate out of the cubital
tunnel during elbow flexion
• Subluxation can be captured
on dynamic imaging
61. JOINT ASSESSMENT
• Play a helpful role in the diagnosis and follow-up of
both inflammatory and noninflammatory arthropathy
• May guide diagnostic and therapeutic procedures
• Follow-up
62. JOINT EFFUSION
• Joint effusions are frequently present in
patients with inflammatory arthritis
• Nonspecific
• The diagnosis of an effusion rests on the
visualization of increased volume of joint
fluid.
• Normal joints contain just a trace of fluid
• Increase in fluid volume constitutes a joint
effusion
63. SYNOVITIS
• Presence of intraarticular non displaceable
hypoechoic to hyperechoic soft tissue
• Demonstrates hyperemia on color doppler
assessment
• On doppler assessment, the velocity filter should be
set to detect low amounts of flow
• Gain settings should be low be adjusted to just below
a level where noise is visualized
64.
65. GRADES OF SYNOVIAL HYPEREMIA
• Grade I (low) hyperemia consists of the visualization
of several single vessel dots
• Grade II (moderate) hyperemia is shown when there
are confluent vessel signals occupying less than half
of the visualized synovial tissue
• Grade III (high) represents confluent vessel signals in
more than half of the synovium
66. BONE EROSION
• Erosive inflammatory arthritis such as
rheumatoid arthritis, erosions can be
depicted on ultrasound as a cortical
defect visible in two perpendicular
planes
• May be graded as small (<2 mm),
moderate (2-4 mm), or large (>4 mm
• More sensitive than plain
radiographs in the detection of bone
erosion
68. GOUT
• Common inflammatory arthritis with a predilection for
1st metatarsophalangeal joint involvement
• Caused by precipitation of uric acid crystals within
joints
• Joint effusion, synovial hypertrophy and
hyperemia, soft tissue swelling, and juxta articular
erosions
69. GOUT
• Intraarticular crystals : presence of a characteristic
irregular hyperechoic line along the surface of the
normally hypoechoic cartilage, termed the “double
contour sign
72. GANGLION CYST
• Mucin-filled lesions most often found at the wrist
• Closely related to a joint or tendon sheath
• 10% of ganglion cysts occur secondary to trauma
• Most common location is adjacent to the
scapholunate articulation
• Well-circumscribed, oval or lobulated anechoic
cystic masses, with accompanying through
transmission
73. GANGLION CYST
• Ganglion cysts may demonstrate low-
level internal echoes and may be
septated
• Noncompressible (as opposed to
bursae, which are compressible)
• Ganglion cysts do not usually
demonstrate internal flow on color
doppler evaluation
74. BAKER CYST
• Occurs in the medial aspect of the popliteal fossa,
• Caused by fluid distention of the semimembranosus
gastrocnemius bursa, occurring between the distal
semimembranosus tendon and the medial head of the
gastrocnemius muscle with a narrow neck arising
from the underlying knee joint
76. BAKER CYST
• Underlying cause : joint effusion, osteoarthritis,
posterior horn medial meniscal tear, inflammatory
arthritis, and internal derangement
• Anechoic, may have a variable appearance, with
complex fluid and hemorrhage, internal septations
and debris, and thick, echogenic, hyperemic synovium
lining the cyst
• Rupture: mimic deep venous thrombosis or
developing cellulitis
78. LIPOMAS
• Occur within the subcutaneous tissues, muscle, or deep soft tissues
• Homogeneously isoechoic, or slightly hyperechoic to fat, with well defined
margins and internal wavy septations mimicking the surrounding
• Painless, mobile, and compressible with transducer pressure
• Do not demonstrate internal complexity or hypervascularity
• Exclude underlying liposarcoma in the evaluation of any suspected lipoma
with following atypical features:
79.
80. LIPOMAS
Exclude underlying liposarcoma in the evaluation of
any suspected lipoma with following atypical features:
• Deep acoustic shadowing
• Internal complexity
• Hypervascularity
• Size greater than 5 cm
• Deep or intramuscular location
• Pain, or history of enlargement
82. NERVE SHEATH TUMORS
• Well-circumscribed solid hypoechoic masses, ovoid or
fusiform in shape, and have faint deep acoustic
enhancement
• A contiguous nerve of origin of the lesion may be
identified, either centrally within the lesion in the case
of neurofibroma or peripherally related to the lesion
in a schwannoma
• An echogenic capsule may be seen, and occasionally
cystic spaces can occur in a degenerated schwannoma
83. NERVE SHEATH TUMORS
• A split-fat sign: comprises the presence of a rim of fat
about the end of the lesion, representing fat normally
present about the neurovascular bundle from which
the lesion arises
• Malignant lesions :
• Poorly defined
• Increasing in size
• Internally heterogeneous in appearance due to internal
necrosis and/or hemorrhage
91. SCAN TECHNIQUE
• Standard protocol is suggested with comprehensive
evaluation in every case, rather than targeted
scanning
• Patient should be sitting upright if possible, either on
a rotating stool or at the edge of a bed
• Likewise, the sonographer should also sit on a
rotating stool, with the seat position somewhat higher
than the patient’s
• High-frequency 12- to 15-mhz linear array transducer
is used to permit high-resolution scanning
92. BICEPS TENDON EVALUATION
• Arm in a neutral position, resting the
forearm on the patient’s ipsilateral
thigh, with elbow flexed and the palm
up
• 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
93. SUBSCAPULARIS TENDON
EVALUATION
• Patient’s arm at the side, in external
rotation with the palm facing up
• Coracoid process of the scapula,
medial to the subscapularis and
palpable in many patients, is a useful
anatomic landmark when locating the
subscapularis tendon
• Patient’s arm can be rotated from
external rotation to neutral position,
while observing the passage of the
tendon fibers deep to the coracoid
process to assess for sub coracoid
94.
95. SUPRASPINATUS EVALUATION
• The normal supraspinatus should appear
smooth, echogenic, and fibrillar tapering
at its insertion or “footprint” with a so
called “bird’s beak appearance’
• Normal rotator cuff tendons possess a
fibrocartilaginous interface at their bony
attachment : a thin hypoechoic band
paralleling the insertional cortex similar
in echogenicity to hyaline cartilage
96.
97. INFRASPINATUS TENDON
• The normal muscle is hypoechoic and
positioned below the scapular spine in the
infraspinatus fos
• 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
98. ROTATOR CUFF MUSCULATURE
EVALUATION
• 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
• The normal muscle should be hypoechoic and
convex in contour, and should fill the
supraspinatus fossa
• To image the infraspinatus and teres minor
muscles, the transducer is moved distal to the
scapular spine, remaining perpendicular to the
spine
101. TENDINOSIS
• No inflammatory component
• Mucoid degeneration and chondroid
metaplasia are present
• On ultrasound, tendinosis appears
heterogeneous or hypoechoic, with
tendon thickening, and loss of the
normal fibrillar pattern
102. FULL THICKNESS ROTATOR CUFF TEARS
• Hypoechoic or anechoic gap within the rotator cuff which may also have a
concave contour at its bursal border
• Greatly retracted tear ( retraction > 3 cms) can result in non visualization of
the rotator cuff tendon
• Gap between the retracted tendon end and the greater tuberosity or distal
tendon stump may be filled with hypoechoic fluid or echogenic debrisand
granulation tissue
• Alternatively, the subacromial-subdeltoid bursa (frequently thickened) and
the deep surface of the deltoid muscle may occupy the defect created by the
tear
104. PARTIAL THICKNESS TEAR
• Focal area of hypo echogenicity
or mixed echogenicity involving
one side of the tendon, but not
extending through the entire
thickness
105. PARTIAL THICKNESS TEAR
• Bursal-sided partial-thickness
tears occur superficially, just
deep to the subacromial
subdeltoid bursa
• Articular-sided tears occur at
the undersurface of the tendon
in contiguity with the joint space
106. PARTIAL THICKNESS TEAR
• Intrasubstance tears can occur either
within the substance of the tendon footprint
at the enthesis or longitudinally within the
tendon fibers
• Rim-rent” tear occurring at the articular
side of the supraspinatus tendon extending
into the tendon footprint on the greater
tuberosity
• most commonly seen in athletes who engage
in overhead-throwing activities
109. MUSCLE ATROPHY
• Characterized by decreased
muscle bulk and increased
muscle echogenicity
(related to increased fat
interposed among muscle
fibers
• Lack of clarity of the muscle
contour and loss of
visibility of the central
tendon within the
myotendinous junction
110.
111. SUBACROMIAL-SUBDELTOID BURSA
• Visualized superficial to the rotator
cuff tendons, deep to the deltoid
muscle and acromion
• At its inferolateral aspect, it extends
beyond the lateral margin of the
rotator cuff, lying superficial to the
humeral shaft
Lateral elbow: examples of hyperechoic (HYPER), isoechoic (ISO), hypoechoic (HYPO), anechoic (AN). (b) Short-axis view of
hyperechoic median nerve (MN) and anechoic ulnar artery (UA)
Figure 5.10 shows acoustic shadowing from the scaphoid in
the volar wrist.
Normal Muscle. (A) In short-axis view a normal vastus lateralis (VL) muscle demonstrates a speckled or “starry sky” appearance
(arrows). (B) In long-axis view the normal muscle demonstrates a pennate appearance (arrows). F, Femur; VI, vastus intermedius.
Muscle Tear. Long-axis image of the medial groin region
demonstrates hypoechoic fluid (arrows) at the pubic symphysis (P) origin
of the adductor muscles, consistent with a grade III muscle tear.
Medial Head Gastrocnemius Tear From the Aponeurosis. (A) Long-axis image shows blunting and retraction of the medial head
gastrocnemius fibers (arrows) from the aponeurosis (*) with an associated hematoma (arrowheads). (B) Short-axis image shows effacement of
the normal gastrocnemius muscle (G) architecture and a hematoma of mixed echogenicity at the site of the tear from the aponeurosis (arrowheads).
S, Soleus muscle.
Forearm Muscle Herniation. At the site of the palpable
abnormality, there is focal herniation of a portion of the pronator teres
muscle (PT) (arrows) through the muscle fascia (arrowheads). This patient
noticed a forearm bulge while weightlifting. U, Ulna.
Ultrasound of the abnormal right side shows marked volume loss in the rectus femoris muscle (arrows) with echogenic fatty infiltration of the
remaining muscle. (B) The normal left side demonstrates normal muscle bulk and echotexture
the normal tendon demonstrates a fibrillar appearance (arrows). (B) In short-axis
view, the tendon is ovoid and echogenic with a speckled appearance (arrows)
Achilles tendon demonstrates fusiform, hypoechoic
swelling of the tendon (arrowheads), although the fibrillar
architecture can still be discerned
the Achilles tendon
at the insertion on the calcaneus is thickened and hypoechoic
with loss of the normal fibrillar pattern (arrows). There is
marked hyperemia on color Doppler imaging. Note the dorsal
calcaneal enthesophytes (arrowheads). C, Calcaneus
focal anechoic clefting of the anterior fibers of the Achilles distal insertion
(arrows) although the posterior fibers remain intact. (B) Color Doppler imaging in the same patient demonstrates marked hyperemia in the injured
tendon.
focal anechoic clefting of the anterior fibers of the Achilles distal insertion
(arrows) although the posterior fibers remain intact. (B) Color Doppler imaging in the same patient demonstrates marked hyperemia in the injured
tendon.
In this patient with rheumatoid arthritis and ankle pain, the peroneus brevis tendon (*) in long-axis (A) and short-axis
(B) views is thickened and heterogeneous. The tendon sheath contains a large amount of echogenic synovium (arrows), hypoechoic fluid, and
hyperemia on color Doppler imaging.
permits high-resolution imaging of small ligaments
in planes that can be individualized to the structure of interest
in any given patient, overcoming some intrinsic difficulties that
can be encountered with scan plane prescription for MRI.
static imaging, dynamic assessment may provide
additional diagnostic information
Normal Anterior Talofibular Ligament. Note that the
ligament (arrows) demonstrates a fibrillar appearance and that the fibers
are more densely packed than those seen in a normal tendon. F, Fibula,
T, talus.
The anterior talofibular ligament (arrows) is diffusely thickened and hypoechoic, with intact fibers, consistent
with sprain. Note the cortical irregularity at the lateral fibula (*) consistent with prior avulsion. F, Fibula, T, talus.-
history of multiple ankle sprains, the anterior talofibular ligament is absent and
the joint is widened on dynamic stress maneuver. Hypoechoic fluid (*) appears in the lateral recess
The medial joint is 2 mm (calipers) wide at rest in this patient with an
ulnar collateral ligament (UCL) tear. Note the UCL is markedly thickened at the proximal humeral attachment and a hypoechoic cleft is present
within the ligament consistent with a tear (arrows). (B) With valgus stress, the medial joint space widens to 4 mm, confirming the presence of a
UCL tear. The overlying common extensor tendon (*) is intact. ME, Medial epicondyle of the humerus; U, ulna.
The ulnar collateral ligament (arrows) of the thumb is torn and the stump is retracted proximal to the metacarpophalangeal
joint and to the adductor aponeurosis (arrowheads), which is thickened and hypoechoic MC, Metacarpal; P, proximal phalanx
In long axis, thenerve demonstrates a fascicular appearance (arrows), although coarser than a tendon. The hypoechoic fascicles are distinguishable
from the intervening echogenic epineurium.
In short axis, at the level of the carpal tunnel, the echogenic tendons (arrows) are seen adjacent to the median nerve (arrowheads).
Caution should be exercised in primary interpretation of longitudinal sonographic images of peripheral nerves because of the potential to scan in a plane, which is not parallel to the nerve with potential artifactual changes in caliber and echogenicity
At rest, with the elbow extended and the probe positioned between the medial epicondyle
(M) and the ulnar olecranon (O), the ulnar nerve (circled) is positioned posterior to the epicondyle. Note the ulnar nerve is enlarged at this location.
(B) On flexion the ulnar nerve (circled) dislocates anterior to the medial epicondyle along with the medial head (MT) of the triceps muscle (known
as “snapping triceps” syndrome). Most patients with ulnar dislocation do not exhibit medial head triceps dislocation
as they may also occur in patients with osteoarthritis, with infection, and in the s
Anechoic fluid is present
within the suprapatellar recess of the knee (arrows). There is concomitant
quadriceps tendinosis (*). F, Distal femur; P, patella.etting of trauma or internal derangement
Complex Ankle Joint Effusion in Rheumatoid Arthritis. (A) A long-axis image of the tibiotalar joint demonstrates a complex joint
effusion (arrows) with both anechoic fluid and echogenic, thickened synovium consistent with synovitis. (B) Color Doppler imaging of the tibiotalar
joint demonstrates marked hyperemia within the echogenic synovium. T, Talus.
Bone Erosions in Two Different Patients Rheumatoid Arthritis. (A) Long-axis gray-scale image at the fifth metatarsophalangeal
joint demonstrates bone erosion in the fifth metatarsal head (arrow) with associated cortical irregularity and synovial hypertrophy (arrowheads). M,
Metatarsal, P, proximal phalanx. (B) Color Doppler imaging of the dorsal wrist in long-axis view demonstrates hyperemia within the synovium and
erosion (arrow) of the scaphoid (S). R, Distal radius, T, trapezium.
. Long-axis image of the Achilles tendon demonstrates hypoechoic nodular thickening
(*) of the posterior tendon surface, consistent with rheumatoid nodules.
Long-axis gray-scale image of the first metatarsal phalangeal joint demonstrates the “sugar
icing” appearance where echogenic urate crystals are deposited along the synovial lining of the joint (arrowheads). The “double contour sign”
is formed by the echogenic urate crystals (“sugar icing”) layering on the anechoic hyaline cartilage with the underlying echogenic cortex (arrows).
(B) Long-axis gray-scale image of the fifth metatarsal phalangeal joint shows a large erosion (arrow) with a large amorphous tophus (arrowheads),
part of which extends into the erosion. M, First metatarsal, P, first proximal phalanx.
Long-axis gray-scale image of the fifth metatarsophalangeal joint demonstrates osteophyte formation (arrows) at
both sides of the joint. M, Metatarsal, P, proximal phalanx.
Long-axis image of the radiocarpal joint at the radioscaphoid articulation demonstrates a lobulated, hypoechoic
ganglion cyst (arrows) arising from the region of the scapholunate ligament. Note the neck (arrowhead) arising from the joint. R, Radius, S,
scaphoid.
Long-axis image of the radiocarpal joint at the radioscaphoid articulation demonstrates a lobulated, hypoechoic
ganglion cyst (arrows) arising from the region of the scapholunate ligament. Note the neck (arrowhead) arising from the joint. R, Radius, S,
scaphoid.
Short-axis image from the medial posterior knee shows a lobulated, septated, hypoechoic Baker cyst (arrows)
communicating with the joint between the medial gastrocnemius muscle (M) and the semimembranosus tendon (S). F, Posterior medial femoral
condyle. (B) In a different patient, long-axis image from the posterior medial knee demonstrates an ovoid, septated complex Baker cyst (arrows)
with internal debris, lined with echogenic synovium.
Longitudinal sonogram of the calf with extended field of view shows a complex mass (arrows) that is
connected to a small amount of fluid in the popliteal fossa (representing the ruptured Baker cyst.
simple lipoma (arrows) is isoechoic to the adjacent subcutaneous fat and contains thin echogenic septations that
parallel the skin surface. (B) Color Doppler imaging demonstrates two small vessels traversing the lipoma. There is no hyperemia.
A myxoid liposarcoma demonstrates mildly increased through transmission (arrows) due to the myxoid content.
However, the mass is solid, with internal echoes. The superficial border is microlobulated. (B) Color Doppler imaging demonstrates increased blood
flow within the mass.
Long-axis image obtained at the site of a palpable mass shows an ovoid, hypoechoic mass with smooth borders, arising from the ulnar nerve. Note the ulnar nerve enters and exits the mass (arrows). (B) A short-axis image of the forearm demonstrates the mass in the expected location of the ulnar nerve. Color Doppler shows marked hyperemia within the mass. FCU, Flexor carpi
ulnaris; FDS, flexor digitorum superficialis and profunda.
A wood splinter is embedded within the dorsal soft tissues of the hand. The splinter (arrowheads) appears
as a linear, echogenic structure.
Normal subcutaneous fat in the lateral nonaffected ankle is juxtaposed with t
abnormal contralateral ankle in the same patient with cellulitis. Note the hypoechoic echotexture of the normal fat (left side of image) versus the echogenic, swollen subcutaneous fat with obscuration of the normal internal septations (right side of image)
Color Doppler imaging demonstrates increased blood flow within
the echogenic, swollen subcutaneous fat.
(D) Gray-scale imaging in a different patient with cellulitis demonstrates anechoic fluid (arrows) within the echogenic cellulitic tissue.
(A) Short-axis image of a complex fluid hypoechoic collection (arrows) with echogenic peripheral soft tissue rind
and increased through transmission, consistent with an abscess. (B) Color Doppler image demonstrates hyperemia within the surrounding soft
tissues. U, Ulna.
Photograph of the probe position for imaging the LHBT in short axis. The patient’s shoulder is externally rotated, with the elbow flexed and held tight to the body, with the forearm palm up, resting on the patient’s lap. This position rotatesthe LHBT anteriorly.
(B) Short-axis image of LHBT (arrow). (C) Photograph of probe position for imaging the LHBT in long axis. The probe is rotated
90 degrees to the short-axis starting position. Patient position remains the same as for the short-axis image. (D) Long-axis image of LHBT
(arrowheads).
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 (
Probe position for supraspinatus in long axis, with the patient in the modified
Crass position. The patient places her arm behind her back, palm on the ipsilateral back pocket, with the elbow straight back, as tight to the body
as possible. This position rotates the supraspinatus from underneath the acromion. This position is usually better tolerated by patients who have
a rotator cuff tear. (A) The probe is placed somewhat obliquely, directed toward the patient’s ear. (B) Long-axis image of the supraspinatus tendon
(arrowheads). (C) Short-axis probe position. The patient remains in the modified Crass position and the probe is rotated 90 degrees from the
long-axis starting position. (D) Short-axis image of the supraspinatus tendon (arrowheads). Note that the long head of biceps tendon is visualized
anterior to the supraspinatus tendon (arrow).
Long-axis probe position. The patient can simply rest the arm at the side, with the forearm palm up in
the lap. The probe is placed under the scapular spine and moved laterally to see the distal insertion on the greater tuberosity. (B) Long-axis image
of infraspinatus tendon (arrowheads). (C) Short-axis probe position. The probe is rotated 90 degrees to the infraspinatus long-axis starting position.
(D) Short-axis image of infraspinatus tendon (arrowheads
A) Probe position for supraspinatus muscle. The probe is placed at the top of the shoulder, medial to
the acromioclavicular joint, and posterior to the clavicle. (B) Probe position for infraspinatus and teres minor muscles. The probe is placed 90
degrees to the scapular spine, just inferior to the scapular spine (arrowheads). (C) Extended field-of-view image of supraspinatus (straight arrow),
infraspinatus (arrowheads), and teres minor (curved arrow). Note the spine of the scapula (*) separating the supraspinatus and infraspinatus muscles
Long-axis image of the supraspinatus tendon (arrowheads) demonstrates hypoechogenicity and diffuse loss of normal fibrillar echotexture.
Long-axis image of the anterior supraspinatus tendon demonstrates intact fibers (arrowheads). (B) Long-axis image of more posterior
fibers of supraspinatus show a full-thickness tear with hypoechoicfluid (arrow) within the gap between the torn tendon end (arrowheads)
and the greater tuberosity (*). (C) Short-axis image of supraspinatus.Intact anterior fibers (white arrowhead) are shown, with a fluid-filled
gap (straight arrow) at the posterior supraspinatus tear. Intact anteriorinfraspinatus fibers (curved arrow) are visible posterior to the tear.
Assisting in orientation, the long head biceps tendon (black arrowhead)appears anteriorly
Focal Full-Thickness Tear of Supraspinatus Tendon.
In this long-axis image of the supraspinatus tendon, there is a focal
full-thickness tear, and the gap between the tendon retracted end and
the greater tuberosity is filled with echogenic debris (arrow) and fluid.
Full-Thickness Supraspinatus Tear With Associated
Cartilage Interface Sign. A hyperechoic line (arrowheads) is seen along
the surface of the normal hypoechoic cartilage (arrow), along the superior
aspect of the humeral head
Long-axis image of supraspinatus shows a heterogeneous (arrows) but intact supraspinatus
tendon, and irregularity of the greater tuberosity (arrowheads).
Fatty Atrophy of the Infraspinatus Muscle. Image obtained of the short axis of the infraspinatus tendon shows low-volume,
hyperechoic infraspinatus muscle (arrowheads), compared with the normal echogenicity of the teres minor
On ultrasound, normally consists of a thin hypoechoic band measuring less than 2 mm where synovial fluid resides within the bursa, and a thin hyperechoic line superficial and deep to this, representing the wall of the bursa and peribursal fat
increased fluid in the subacromial bursa (straight arrow), and
thickening of the wall of the subacromial bursa (arrowheads). Note also
a small bursal-sided tear of the supraspinatus at its insertion (curved
arrow).
Longaxis image of the supraspinatus image demonstrates a hyperechoic
focus of calcification (arrowheads) within the supraspinatus tendon.
Short-axis image shows increased fluid within the long head biceps tendon sheath
(arrowhead), surrounding the tendon (arrow). (B) Short-axis image shows hyperemia (arrowheads) in the long head of biceps tendon sheath.
Short-axis image demonstrates a hypoechoic cleft (arrow) through
the long head of biceps tendon, dividing it into two components.
. Image of the acromioclavicular joint demonstrates osteophyte formation at the distal clavicle (arrow) and capsular thickening and hypertrophy (arrowhead).
. Image of the posterior shoulder shows increased fluid within the joint (arrow) in this patient with osteoarthritis.
