MR Imaging of the Rotator Cuff
Timothy G. Sanders, M.D.
MRI Technique
-T1 and T2 FS
-Oblique Coronal
-T1 and T2 FS
-Oblique Sagittal
-T2 FS and GRE
-Axial
Osseous Outlet and Acromion
• Rotator Cuff Surrounded by a Bony Arch
• Mechanical Impingement leads to
degeneration of the cuff
• Anterior Acromion Most Important
Structure Leading to Impingement
Normal Osseous Outlet
Clavicle
Coracoid
Acromion
Acromial Types
Type I
Acromial Types
Type II
Acromial Types
Type III
Acromial Types
Type IV
Acromial Down Sloping
Anterior Down Sloping Evaluated on Sagittal Images
Axis of Acromion
Normal Axis of Acromion
Anterior Down Sloping
Acromial Down Sloping
Lateral Down Sloping Evaluated on Coronal Images
Axis of Acromion
Normal Axis of Acromion
Lateral Down Sloping
Acromial Spur
-Spur
-Deltoid Tendon (Mimics Spur)
-Contains Marrow Signal
-Black (No Marrow Signal)
Os Acromiale
Os Acromiale
Ossification Center Usually Closes by 22-25 y.o.
Normal Appearing Anterior Acromion on Axial Image
Os Acromiale (Axial Images)
-Can be unstable resulting in impingement of Rotator Cuff
during contraction of the deltoid
Os Acromiale (Sagittal Images)
Normal AC Joint
“Double” AC Joint Sign
Os Acromiale
AC Joint
Os Acromiale
“Double” AC Joint
Acromion
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Type (I, II, III)
Anterior/ Lateral Down Sloping
Inferior Spur
Os Acromiale
Coracoacromial Ligament
-Normal Ligament <3 mm
-Thick Ligament can Impinge
on Anterior Rotator Cuff
Acromioclavicular Joint
-AC degenerative change,
capsular hypertrophy
-Cuff less rigidly confined
-Does it cause mass effect
on rotator cuff?
AC Joint Sprain/Separation
Grade I
Grade II
-Capsular edema, effusion
-Capsular edema, effusion
-No elevation
-Elevation distal clavicle
Osteolysis of Distal Clavicle
Post-traumatic osteolysis
-Complication of trauma
(occurs within 2 months of
injury, self limiting)
-Repetitive stress (wt.
lifters)
-X-ray: loss of normal
cortical line- distal clavicle
Coracoid Impingement
-Normal Coracohumeral
Distance is 11 mm
-Narrowed C-H Distance can
Impinge on Subscapularis
Osseous Outlet and Acromion
• Acromion
– Type, Down Sloping, Spur, Os Acromiale
• AC Joint
– Deg. Change, Hypertrophy (mass effect?)
• Coracoacromial Ligament (thickened?)
• Coracohumeral Impingement (subscap?)
Rotator Cuff (Sagittal)
Supraspinatus;
Infraspinatus; Teres Minor;
Subscapularis
Rotator Cuff (Coronal)
-Primary Plane for Evaluating
the Supraspinatus Tendon
-Musculotendinous Junction at
12:00 Position
Rotator Cuff (Axial Plane)
-Supraspinatus Tendon
Rotator Cuff (Axial Plane)
-Primary Plane for
Evaluating Subscapularis
-Infraspinatus
Located Posteriorly
Rotator Cuff (Coronal)
- Infraspinatus
-Subscapularis
- Located Posteriorly
- Located Anteriorly
- Slopes upward
- Multi-slip tendon
Rotator Cuff Pathology
• Tendonopathy
• Tear
– Partial Thickness, Full Thickness, Complete
• Musculotendinous Retraction
• Fatty Atrophy
• HADD/ Calcific Tendonitis
Tendonopathy
-Increased T1-signal; thickened/ attritional changes (thinned)
-Intermediate T2-signal (No Fluid Signal)
Partial Thickness Tear (Articular)
-T2: Fluid Signal extending
into black tendon
-Partial Thickness
Undersurface Tear
Partial Thickness Tear (Bursal)
-Fluid Signal Extending into
the Bursal Surface of the
Supraspinatus Tendon
Partial Thickness Tear (Interstitial)
-Fluid Signal within the
Substance of the Tendon
-Does Not Involve the
Articular or Bursal Surface
Intramuscular Cyst Rotator Cuff
-High Association with
1. P.T. Undersurface Tear
2. Small F.T. Tear
3. DDX: Paralabral Cyst
Intramuscular Cyst Rotator Cuff
-Intramuscular Cyst Supraspinatus
-Small Undersurface P.T. Tear
Delamination (retraction of deep fibers)
Full Thickness Tear
-Fluid extends through the entire thickness of the tendon
(superior to inferior)
-Mild retraction of musculotendinous junction
Massive Tear
Musculotendinous retraction
-Measure in centimeters; can affect prognosis
Fatty Atrophy
-Mild, Moderate, Severe
-Streaks of high signal on T1
-Loss of muscle bulk (Sagittal)
Calcific Tendonitis
-HADD: Dark Globular Area on all Pulse Sequences
-Blooming Artifact on Gradient Echo Images
Subscapularis
-Subscapularis: Attaches to lesser tuberosity
-Extra-articular Biceps: Best Seen on Axial Image
-In Bicipital Groove; Transverse Ligament
Avulsion of Subscapularis
-Subscapularis Muscle can
Avulse off of Lesser
Tuberosity
-Associated with
Dislocation of the Biceps
Tendon
-Seen best in Axial Plane
CH Ligament
Biceps Tendon
(Anatomy)
LHBT
LHBT
•Coracohumeral ligament
primary stabilizer of LHBT
Biceps Tendonitis/ Tear
-Thick Tendon; Increased
Signal
-Intra-articular
-Extra-articular
Biceps Tendon (Anatomy)
•Subscapularis/ transverse humeral ligament
•Secondary stabilizer
Biceps Subluxation: Pattern I
1. CHL: intact
2. Subscapularis tendon: complete tear
- No Dislocation of LHBT
Pattern II: Intra-articular
1. CHL: torn
2. Subscapularis tendon: complete tear
- Intra-articular dislocation of LHBT
Pattern III: Extra-articular
1. CHL: torn
2. Subscapularis tendon: superficial fibers torn
-Extra-articular dislocation of LHBT
Pattern IV: Interstitial
1. CHL: torn
2. Subscapularis tendon: intact
- Subluxation of LHBT into substance of subscapularis
tendon and muscle: interstitial tear
Rotator Cuff Pathology
• Tendonopathy
• Tear
– Partial Thickness, Full Thickness, Complete
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Musculotendinous Retraction
Fatty Atrophy
HADD/ Calcific Tendonitis
Nerve Entrapment Syndromes