Pitfalls and anatomic variants in shoulder MRI and MRA

Filippo Del Grande, MD. Third Musculoskeletal MRI Meeting 2016: shoulder MRI

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Outline presentation

�Shoulder MRI/MRA is one of the most performed musculoskeletal MR exam

�Presentation of a selection of anatomic variants and pitfalls�Osseous and cartilage structures�Glenoid labrum and ligament

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Williams M, et al. Skeletal Radiol. 2006 Dec;35(12):909-14.

Jin W, et al. AJR Am J Roentgenol. 2005 Apr;184(4):1211-5.

� Dorsally located humeral head cysts are common and usually asymptomatic

� Lined with connective tissue and connected to the joint spacePersonal use only

Fritz LB, et al. Radiology. 2007 Jul;244(1):239-48.

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Studler U, AJR Am J Roentgenol. 2008 Jul;191(1):100-6

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1. Lesser tuberosity cysts are associated with subscapularis tendon tears.

2. Lesser tuberosity cysts on radiographs should be reported by the radiologist to prompt clinicians to focus on subscapularis tendon tears.

Studler U, AJR Am J Roentgenol. 2008 Jul;191(1):100-6

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Normal postero-lateral flattening below coracoid process

At level or above the coracoid process

Hills Sachs vs. normal postero-lateral flattening

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Dunham KS, Magn Reson Imaging Clin N Am. 2012 May;20(2):

- Tubercle of Assaki is the thickest subchondral bone area located in the middle of the glenoid and thinning of the cartilage over the glenoid.

- Not to be confused with cartilage lesion/thinning

Cook TS, et al. Magn Reson Imaging Clin N Am. 2011 Aug;19(3):581-94

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� Accessory bone in 5% of the healthy subjects.

� Non union of ossification center during development.

� Normally appear at 15 years of age and fuse at about 20-25 year of age

� Not to be confused with fracture/stress fracture

Courtesy G. Vincenzo, MD

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� Deltoid tendon and coraco-acromial ligament attachment

� Not to be confused with osteophytes

Subacromial pseudo-spurs

Cook TS, et al. Magn Reson Imaging Clin N Am. 2011 Aug;19(3):581-94

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Labral variants

http://www.radiologyassistant.nl/en/p4f49ef79818c2/shoulder-mr-anatomy.html. Access 17.4.2016

Labral variants are located between 11 and 3 O’clock position

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Sublabral foramen� 11 % of the subjects� Detachment of the

labrum of the glenoid located between 1 and 3 O’clock position

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Sublabral recess� Located between 11 and 1 O’clock position.

� Usually run medially/parallel to the glenoid (SLAP lesion usually run laterally)

� Anterior to the biceps anchor� Smooth margins

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� Firm attachment (type 1)� Small recess (type 2)� Deep recess (type 3)

Attachment bicipitolabral complex

De Maeseneer M, et al. Radiographics. 2000 Oct;20 Spec No:S67-81.

De Maeseneer M, et al. Radiographics. 2000 Oct;20

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Buford complex

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MGHL� Most common variation in size

and shape� Absent in 20-30 % of the

patients� In most case ( not always)

originate just below the SGHL and insert on anatomic neck of the humerus.

� Cord-like MGHL and absent antero-superior labrum (about 1-2% of healthy subjects). Buford complexe

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Bifidus MGHL

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IGHL� Most important in the passive stabilization

of the shoulder� Anterior band thicker than posterior band

originating form the glenoid labrum and inserting to the humeral neck

� Thick in adhesive capsulitis, throwing athletes ( baseball,…)

- Jagged ( synovial folds)

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- Jagged ( synovial folds)

Al-Riyami AM, et al. Semin Musculoskelet Radiol. 2014 Feb;18(1):36-44.

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Pitfalls in shoulder MR Imaging/23.4.2016 /

Song KD, et al. AJR Am J Roentgenol. 2011 Dec;197(6):W1105-9

Del Grande F, et al J Comput Assist Tomogr. 2016 Jan-Feb;40(1):118-25.

Thick IGHL

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� Rarely the IGHL can transverse the posterior capsule as a separate round structure mimicking a labral tear.

IGHL variant

Motamedi D et al. AJR Am J Roentgenol. 2014 Sep;203(3):501-7.

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Pitfalls in shoulder MR Imaging/23.4.2016 /

2-o’clock

4-o’clock

7-o’clock

9-o’clock

AnteriorPosterior

Normal vs high origin of IGHL

� Anterior band originate form 2-4-o’clock position. High origin of the anterior band of IGHL above 3-o’clock position. Posterior band originate form 7-9-o’clock position

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Dunham KS, Magn Reson Imaging Clin N Am. 2012 May;20(2):

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Take home message

� Anatomic variants important to know in order to avoid to report pathologies �posterior vs. anterior subchondral cysts.�Labral variants are located between 11 and 3

O’clock position�Great variability of MGHL ( absent, bifidus,

thickness, Buford) �Pay attention to high originating anterior IGHL

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