Shoulder / rotator cuff — Reference values

Shoulder / rotator cuff — Reference values: Minimum shoulder protocol, Technique and positioning, Subacromial-subdeltoid bursa — thickness/fluid.

Shoulder ultrasound should be read by structures, not by a single measurement. The examination is strong for rotator cuff, long head of biceps, subacromial-subdeltoid bursa, superficial acromioclavicular joint, posterior recess and dynamic assessment; it is limited for deep labrum, cartilage, bone marrow and complex instability. The colors below separate consensus normality, borderline or context-dependent zones and consensus abnormal findings.

Measurements and reference values

Measurement	Usual value	Note
Minimum shoulder protocol	biceps, subscapularis, supraspinatus, infraspinatus, teres minor, bursa, acromioclavicular joint, posterior recess and dynamic maneuvers when indicated	Examine seated when possible, adapt to pain and range of motion, document in short and long axis and measure abnormalities in two orthogonal planes.Source: AIUM-ACR-SPR-SRU MSK ultrasound parameter / ESSR shoulder guideline
Technique and positioning	high-frequency linear transducer; forearm supinated for biceps; external rotation for subscapularis; hand in back pocket for supraspinatus; posterior sweep for infraspinatus and teres minor	Avoid anisotropy and remember that forced internal rotation may overestimate supraspinatus tear size.Source: ESSR shoulder technical guideline
Subacromial-subdeltoid bursa — thickness/fluid	<2 mm	Normal fluid is rarely thicker than 2 mm and tends to be posterior; greater than 3 mm, fluid medial to the acromioclavicular joint or anterior to the humerus is abnormal.Green: up to 2 mm, posterior, without hyperemia and without focal painYellow: >2 to 3 mm or small context-dependent fluidRed: >3 mm, anterior/medial fluid, complex content or hyperemia with inflammatory/infectious concernSource: White et al., J Comput Assist Tomogr 2006 / PubMed PMID 16628056
Partial rotator cuff tear — Ellman depth	<3 / 3–6 / >6 mm	Also classify as articular-sided, bursal-sided or intrasubstance; measure depth and extent. Greater than 6 mm usually represents more than half tendon thickness.Green: no focal defect and continuous fibersYellow: Ellman I <3 mm or Ellman II 3-6 mmRed: Ellman III >6 mm or more than 50% thicknessSource: Ellman 1990 / Shoulderdoc classification summary
Full-thickness tear — essential measurements	width in short axis + retraction in long axis	Describe involved tendons, communication with the bursa, retraction, width, muscle bulk and fatty infiltration when visible; compare with the opposite side when useful.Green: no tendon discontinuityRed: full-thickness defect, retraction or large/massive tearSource: AIUM-ACR-SPR-SRU MSK ultrasound parameter
Long head of biceps	centered in the groove, fibrillar, without relevant sheath distention	Assess in short and long axis. Fluid, synovitis or hyperemia suggest tenosynovitis; subluxation/dislocation should raise concern for subscapularis or rotator interval injury.Green: centered, fibrillar, without hyperemiaYellow: tenosynovitis, tendinopathy or mild fluidRed: subluxation, dislocation or tearSource: AIUM-ACR-SPR-SRU MSK ultrasound parameter / ESSR
Shoulder Doppler	bursa, biceps sheath, joint synovium and painful tendon	Color or power Doppler helps detect hyperemia in bursitis, tenosynovitis, synovitis, calcific crisis, postoperative repair or infection.Green: no hyperemia in the right contextYellow: mild or moderate hyperemia without systemic signsRed: intense hyperemia with fever, wound, postoperative status, complex bursa or collectionSource: AIUM-ACR-SPR-SRU MSK ultrasound parameter
Important limitations	deep labrum, cartilage, bone marrow, complex instability and occult fracture	When the clinical question is deep or osseous, ultrasound should guide but not replace radiographs, MRI or CT according to context.Source: AIUM-ACR-SPR-SRU / ESSR

Classifications and calculators

Interactive assistant — shoulder ultrasound

Color	How to interpret
Green	Thin bursa, continuous tendons, centered biceps, no effusion, no hyperemia and no critical limitation in completed fields.
Yellow	Gray zone: tendinopathy, superficial/intermediate partial tear, small bursa, hyperemia without systemic signs, dynamic impingement or deep labral question.
Red	Consensus abnormal or high-impact finding: bursa above 3 mm, full-thickness tear, Ellman III, biceps dislocation, muscle atrophy, pseudoparalysis, fever/infection, suspected fracture/dislocation.

Fill measurements and structures in the panel to generate color, critical points and next step. The assistant does not replace medical judgment or integration with radiographs/MRI.

Source: AIUM-ACR-SPR-SRU / ESSR / PubMed / Ellman

Anatomic structure-by-structure checklist

Structure	How to examine	Do not forget
Long head of biceps	Forearm supinated; short axis in the bicipital groove and long axis to the myotendinous junction.	Confirm position in the groove, sheath fluid, hyperemia, subluxation, dislocation or tear.
Subscapularis	Elbow at the side, external rotation; sweep from myotendinous junction to lesser tuberosity insertion.	Dynamic maneuver helps detect biceps instability and subcoracoid impingement.
Supraspinatus	Hand in back pocket or modified position according to pain; assess long and short axis while keeping the beam perpendicular.	Compress the tendon to reveal a nonretracted tear; measure depth, extent and retraction when a defect is present.
Infraspinatus and teres minor	Posterior sweep below the scapular spine, with internal and external rotation when useful.	Look for atrophy, fatty infiltration, posterior tear and paralabral cyst at the spinoglenoid notch.
Bursa and dynamic impingement	Assess the bursa at rest and during abduction in internal rotation if symptoms suggest impingement.	Pain with bursal/tendon bunching is contextual; bursa above 3 mm is abnormal.
Acromioclavicular joint and posterior recess	Transducer at the shoulder apex for the acromioclavicular joint; posterior transverse plane at the glenohumeral joint space.	Describe osteoarthritis, synovitis, trauma, posterior effusion, paralabral cyst and indirect labral signs.

Source: AIUM-ACR-SPR-SRU / ESSR shoulder guideline

Rotator cuff — color reading

Finding	Green	Yellow	Red
Tendon and echotexture	continuous fibers, compatible thickness/echotexture, no focal pain	tendinopathy, calcification, hypoechogenicity or compression pain	complete discontinuity, retraction or large defect
Partial tear	no focal defect	Ellman I <3 mm or Ellman II 3-6 mm; state articular, bursal or intrasubstance side	Ellman III >6 mm or more than 50% thickness
Full-thickness tear	not present	suspicion limited by pain, anisotropy or incomplete window	defect crossing full thickness, communication with bursa, retraction or massive tear
Rotator cuff muscles	preserved and symmetric bulk	mild atrophy or difficult comparison	evident atrophy/fatty infiltration, especially with tear

Source: AIUM-ACR-SPR-SRU / Ellman

Bursa, biceps and Doppler — practical interpretation

Structure	Green	Yellow	Red
Subacromial-subdeltoid bursa	up to 2 mm, posterior, without hyperemia	>2-3 mm or small context-dependent fluid	>3 mm, anterior/medial fluid, complex content or marked hyperemia
Long head of biceps	centered, fibrillar, without relevant fluid	tenosynovitis, tendinopathy or mild fluid	subluxation, dislocation or tear
Doppler	no hyperemia in the right context	mild/moderate hyperemia without systemic signs	intense hyperemia with fever, wound, postoperative status, complex bursa or collection
Acromioclavicular joint	no focal pain or distention	osteoarthritis, osteophytes or capsulitis/synovitis	suspected separation/dislocation or infection

Source: PubMed PMID 16628056 / AIUM-ACR-SPR-SRU

Useful shoulder differential diagnoses

Presentation	Consider	Role of ultrasound
Lateral pain and painful arc	supraspinatus tendinopathy, bursitis, subacromial impingement, calcific tendinopathy	assess cuff, bursa and dynamic maneuver; Doppler helps in active phase
Anterior pain	biceps, subscapularis, rotator interval, acromioclavicular joint	confirm biceps in groove, fluid, hyperemia, subluxation and subscapularis tendon
Global stiffness	adhesive capsulitis, arthropathy, pain limitation, postoperative state	ultrasound may show synovitis/bursa, but diagnosis is clinical and may require MRI
Acute trauma or sudden strength loss	complete tear, avulsion, occult fracture, dislocation, biceps injury	measure tear and retraction; radiographs/MRI according to bone or surgical concern
Neurologic weakness or atrophy	suprascapular nerve compression, paralabral cyst, neuropathy, chronic tear	look for cyst at the suprascapular/spinoglenoid notch and compare muscles
Fever, wound or painful postoperative state	infection, abscess, septic bursa, collection, retear	Doppler, complex content and guided aspiration may change management

Source: AIUM-ACR-SPR-SRU / ESSR / MSK ultrasound reviews

Teaching checklist for the shoulder report

Item	Safety question
Structure-based protocol	Were biceps, subscapularis, supraspinatus, infraspinatus/teres minor, bursa, acromioclavicular joint and posterior recess documented?
Measurements	Does a partial tear have depth and side? Does a full-thickness tear have width and retraction?
Doppler and dynamics	Was hyperemia documented when there was pain, bursa, fluid, postoperative state or inflammatory concern? Was impingement tested when indicated?
Priority-changing findings	Were full-thickness tear, Ellman III, bursa above 3 mm, biceps dislocation, fever, collection, pseudoparalysis or suspected fracture/dislocation highlighted?
Limitations	Was it stated when labrum, cartilage, deep bone, pain or mobility limited the examination?

Source: AIUM-ACR-SPR-SRU / ESSR

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