Demystifying ABER (ABduction and External Rotation) sequence in shoulder MR arthrography

Area of Science:

• Radiology
• Orthopedic Imaging
• Musculoskeletal MRI

Background:

• The abduction and external rotation (ABER) sequence in shoulder MR arthrography is crucial for visualizing specific glenohumeral joint structures under stress.
• Key structures like the supraspinatus tendon, glenoid labrum, and inferior glenohumeral band are better depicted in the ABER position.
• Underutilization and improper assessment of the ABER sequence stem from practical setup difficulties and unfamiliarity with image alignment.

Purpose of the Study:

• To provide a step-by-step guide for planning the ABER sequence in shoulder MR arthrography.
• To emphasize the importance of scout series setup for optimal ABER imaging.
• To present a clear outline of the anatomical landmarks visible on ABER images.

Main Methods:

• Detailed explanation of ABER sequence planning.
• Emphasis on scout series acquisition and setup.
• Illustrative guide to anatomical landmarks in ABER images.

Main Results:

• A simplified, step-by-step approach to ABER sequence planning is presented.
• Guidance on scout series setup facilitates proper ABER imaging.
• Anatomical landmarks on ABER images are clearly outlined for improved interpretation.

Conclusions:

• The ABER sequence offers significant benefits for shoulder MR arthrography by imaging structures under relevant stress.
• This technical note aims to overcome practical challenges, promoting wider and more accurate use of the ABER sequence.
• Improved understanding of ABER sequence setup and interpretation enhances diagnostic accuracy for shoulder pathologies.