MR Imaging of SLAP Lesions

Abstract

Background:SLAP lesions of the shoulder are challenging to diagnose by clinical means alone. Interpretation of MR images requires knowledge of the normal appearance of the labrum, its anatomical variants, and the characteristic patterns of SLAP lesions. In general, high signal extending anterior and posterior to the biceps anchor is the hallmark of SLAP lesions. Common diagnostic criteria for a SLAP lesion by MR or MR arthrography include the following: presence of a laterally curved, high signal intensity in the labrum on a coronal image, multiple or branching lines of high signal intensity in the superior labrum on a coronal image, full-thickness detachment with irregularly marginated high signal intensity and/or separation >2 mm on conventional MRI or 3 mm on MR arthrography between the labrum and glenoid on a coronal image, and a paralabral cyst extending from the superior labrum.Methods:MR diagnosis of SLAP tears may be improved with provocative maneuvers, such as longitudinal traction of the arm or positioning of the shoulder in abduction and external rotation during imaging. The use of intra-articular contrast distends the joint similar to what occurs during arthroscopy and forced diffusion under the labrum may improve the ability to detect SLAP lesions that might not be seen with standard MR. Improved diagnostic accuracy for SLAP tears is seen with 3-T compared with 1.5-T MR imaging, with or without intra-articular contrast material.Conclusion:Regardless of MR findings, however, physicians should be cautious when recommending surgery in the patient with a vague clinical picture. The patient’s history, physical exam, and imaging evaluation all should be considered together in making the decision to proceed with surgery.

Diagnostic performance of 3D-multi-Echo-data-image-combination (MEDIC) for evaluating SLAP lesions of the shoulder

“…years of professional experience in musculoskeletal imaging using a picture archiving and communication system (Centricity PACS, Version 4.0, GE Healthcare IT Solutions, Barrington, IL) and FDA cleared diagnostic monitors (EIZO RadiForce RX211, Eizo Corporation, Hakusan, Japan). Both 3D-MEDIC and 2D-PD fs images were evaluated separately and binarily for the presence or absence of SLAP lesions according to diagnostic criteria published in the literature (Table 2) [1]. Both radiologists were in control over slice selection, magnification, and level of windowing.…”

“…Superior labrum anterior to posterior (SLAP) lesions are lesions of the attachment of the long biceps tendon and the adjacent anterosuperior to posterosuperior labral attachment to the glenoid bone, collectively forming the SLAP complex [1, 2]. The overall incidence of SLAP lesions ranges from 6 to 12% in the overall population, and reaches 28–32% in certain risk groups such as overhead athletes or military personnel [3–5].…”

Postoperative Knee and Shoulder

“…If conventional MR is inconclusive, MR arthrography can be performed to better assess the status of the postoperative superior labrum. Imaging in slightly exaggerated external rotation will put additional traction on the biceps tendon and thus make superior labral tears more conspicuous [87].…”

Magnetic resonance imaging of the shoulder

“…Care must be taken to not confuse SLAP tears with a sublabral foramen or sublabral recess. MR arthrography has shown better diagnostic accuracy of SLAP tears when comparing 3T to 1.5T, and with manoeuvres like longitudinal traction and ABER [ 79 ]. On MR arthrography, high signal can be seen extending into the superior labrum and possibly into the biceps tendon.…”