MR and MR arthrography to identify degenerative and posttraumatic diseases in the shoulder joint

Superior labral anterior posterior lesions of the shoulder

Superior labrum anterior and posterior (SLAP) lesion is of fairly recent description and its understanding is rapidly evolving. Its incidence and need for surgical treatment has increased exponentially in line with the increase in shoulder arthroscopies. It is of particular importance in the elite over head athlete and the young. A range of arthroscopic techniques and devices have been described with good functional results. The ability to return to pre injury level of sports remains a concern.

Reliability of MRI assessment of supraspinatus tendinopathy

OBJECTIVE

To determine the interobserver and intraobserver reliability of the interpretation of MRIs for supraspinatus tendinosis.

METHODS

In the interobserver trial, the MRIs of 52 athletes' shoulders were observed by 3 observers on one occasion within a 2-month period. All 52 images were read by the most experienced musculoskeletal radiologist on 3 different occasions on separate days without access to the previous readings for the intraobserver trial. Supraspinatus tendinosis was graded using a modified 4-point scale from grades 0 to grade 3.

RESULTS

The grading of MRI-determined supraspinatus tendinosis was reliable, having an intraclass correlation (ICC) of 0.85 when assessed by the single well-trained observer. Interobserver reliability was only fair to good (ICC = 0.55).

CONCLUSIONS

Supraspinatus tendinosis can be accurately identified on MRI with little variation by a single well-trained observer. Interobserver reliability was only fair to good. Our data indicated that the reliability of the assessment was much greater in more experienced radiologists than in those with less experience.

An overview of MR arthrography with emphasis on the current technique and applicational hints and tips

Magnetic resonance (MR) arthrography has been investigated in every major peripheral joint of the body, and has been proven to be effective in determining the integrity of intraarticular ligamentous and fibrocartilaginous structures and in the detection or assessment of osteochondral lesions and loose bodies in selected cases. Several methods could be used to create arthrogram effect during MR imaging, however, direct MR arthrography using diluted gadolinium as the contrast agent is the most commonly used technique and is the most reliable of all. MR arthrography is useful for demonstrating labrocapsular-ligamentous abnormalities and distinguishing partial thickness rotator cuff tears from focal full thickness tears in the shoulder, identifying or excluding recurrent tears following meniscal operations in the knee, demonstrating perforations of the triangular fibrocartilage complex (TFCC) and ligaments in the wrist, showing labral tears in the hip, diagnosing ligament tears in the ankle and identifying osteochondral lesions or loose bodies in any of the aforementioned joints. In this article, an overview of techniques of MR arthrography is provided with emphasis on direct MR arthrography using diluted gadolinium as the contrast agent. The current applications of the technique in major peripheral joints are reviewed, with emphasis given to the shoulder joint where the role of this technique has become well established.

Evaluation of rotator cuff tears with magnetic resonance arthrography

The size and morphologic features of rotator cuff tears may influence treatment selection and affect final outcomes. Magnetic resonance arthrography allows observation of these features and other intraarticular structures. To assess the utility of magnetic resonance imaging in assessing size and morphologic features, we retrospectively reviewed observations on 41 shoulders in 37 consecutive surgically treated patients (mean age, 63.2 years) who had magnetic resonance imaging followed by magnetic resonance arthrography. The maximum rotator cuff defect size in the anteroposterior direction defined transverse size, and the maximum rotator cuff defect size in the mediolateral direction defined longitudinal size. Sensitivities for detecting full-thickness rotator cuff tears by magnetic resonance imaging and magnetic resonance arthrography were 90.2% and 100%, respectively. Maximum longitudinal and transverse dimensions of the tear as shown by magnetic resonance arthrography correlated better with intraoperative measurements (r2 = 0.85 transversely, 0.92 longitudinally) than magnetic resonance imaging measurements (r2 = 0.47 transversely, 0.26 longitudinally). The reproducibility of the two methods is similar. Magnetic resonance arthrography also allowed morphologic classification of the torn tendon as blunt end, tapering end, indistinct end, horizontal tear, and global tear. There was good agreement in classifying torn edges; the imaging findings agreed with findings at surgery. Magnetic resonance arthrography was more accurate in evaluating rotator cuff tear size and morphologic features than conventional magnetic resonance imaging.