From the Research
The best MRI to evaluate a pectoralis muscle tear is a dedicated shoulder MRI with specific attention to the pectoralis major muscle, ideally performed on a high-field strength magnet (1.5T or 3T) with a dedicated shoulder coil, as recommended by the most recent study 1.
Key Considerations
- The protocol should include axial, sagittal, and coronal sequences with T1-weighted, T2-weighted with fat suppression, and proton density sequences.
- Intravenous contrast is generally not necessary for initial evaluation.
- The axial images are particularly important as they best demonstrate the muscle and tendon anatomy, especially at the humeral insertion site where most tears occur.
- The MRI should be performed with the patient's arm positioned at the side in neutral rotation to optimize visualization of the pectoralis major muscle and its tendon.
Rationale
The pectoralis major has a complex anatomy with multiple muscle heads converging into a twisted tendon insertion on the humerus, making specialized imaging necessary to accurately identify the location and extent of tears. Early diagnosis is important as acute tears (less than 6 weeks) have better surgical outcomes than chronic injuries, as noted in 2 and 3.
Supporting Evidence
- A study published in 2023 1 highlights the importance of MRI in diagnosing pectoralis major muscle injury and guiding clinical and surgical management.
- Another study from 2016 2 supports the use of MRI in diagnosing the tear grade and location of pectoralis major tendon ruptures, particularly for acute, tendon-bone, and complete tears.
- The use of MRI in evaluating pectoralis major tears has been consistently supported by various studies, including those from 2016 3 and 1996 4, demonstrating its value in assessing the extent and location of muscle and tendon injuries.