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Duke Orthopaedics
presents
Wheeless' Textbook of Orthopaedics

MRI Imaging of the Shoulder:


- Discussion:
    - used to assess impingement syndromes (coronal oblique views) and less often glenoid pathology (transaxial views);
    - it accurately identifes full-thickness rotator cuff tears;
          - defects show up with high signal intensity traversing supraspinatus tendon on T2 images;
          - MRI is less specific in diagnosing tendinitis & partial tears;
    - external rotation:
          - patients should keep the shoulder in external rotation during the exam;
          - position keeps slight tension on anterior capsular structures;
          - external rotation permits maximum visualization of the supraspinatus insertion, and prevents confusing overlap with the
                infraspinatus tendon on coronal oblique images;
    - signal intensity characteristics:
          - fat suppressed T2 weighted:
                - long repitition time and long echo time
                - water gives bright signal and fat gives very dark signal;
                - allows evaluation of marrow pathology;
          - STIR images:
                - long repitition time and variable echo time;
                - water gives bright signal and fat gives very dark signal;
                - allows evaluation of marrow pathology;
          - gradient echo:
                - short repitition time and short echo time
                - intermediate fat signal and intermediate to bright water signal;
                - for evaluation of articular cartilage, blood, and PVNS;
          - proton density:
                - long repitition time and short echo time;
                - intermediate to high fat signal and intermediate water signal;
                - high resolution for evaluation of labral tears, but poor evaluation of marrow;
          - references:
                - Rotator Cuff: Evaluation with US and MR Imaging.
                - Labral injuries: accuracy of detection with unenhanced MR imaging of the shoulder.

- Specific Views:    (see Anatomy of the shoulder (MR) - Atlas of the human body)
    - transaxial view of the shoulder:
             - evaluates shoulder capsule, glenoid labrum, subscapularis, biceps and for evaluation of a Hill Sachs Lesion;
             - protocols: fat suppressed T2 wt images and proton density weighted images
    - oblique saggital
             - plane is perpendicular to supraspinatus;
             - non fat suppressed T1 wt images and fat suppressed T2 wt images;
             - acromial morphology is best evaluated on sagittal oblique magnetic resonance images;
             - (see radiographic evaluation of impingement syndrome)
             - useful for imaging the subscapularis;  
             - w/ subscapularis tears look for disruption of the transverse ligament;
             - biceps tendon is followed from medial to lateral as it courses from its intra-articular origin on supraglenoid
                    tubercle to its extracapsular location in the bicipital groove laterally;

    - coronal oblique views of the MRI:  
             - protocols: fat suppressed T2 wt images and proton density weighted images

             



- Hagl Lesion:
    - avulsion of inferior ligament from the humerus;
    - references:
          Humeral avulsion of the anterior shoulder stabilizing structures after anterior shoulder dislocation: demonstration by MRI and MR arthrography



Magnetic resonance imaging of the shoulder. Sensitivity, specificity, and predictive value.

Magnetic resonance imaging of the shoulder.

Shoulder instability: evaluation with MR imaging.  

Abnormal findings on magnetic resonance images of asymptomatic shoulders.

The use of MRI about the shoulder. Beltran J. J Shoulder Elbow Surg. 1992;1:321.

Evaluation of the painful shoulder. A prospective comparison of magnetic resonance imaging, computerized tomographic arthrography, ultrasonography, and operative findings.

Rotator Cuff: Evaluation with US and MR Imaging.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Monday, May 21, 2012 10:53 am