– Superior labral anterior-posterior (SLAP) tears are common shoulder injuries, especially in overhead athletes. Clinical diagnosis is challenging, making imaging important.
Normal Anatomy and Variants
– The labrum normally has a triangular structure and uniformly low signal intensity on MRI.
– Anatomic variations like Buford complex, sublabral sulcus, and sublabral foramen occur often in the anterosuperior labrum. These must be distinguished from tears.
– MR arthrography provides joint distension and contrast enhancement, improving detection of labral tears versus standard MRI.
– Higher field strength 3T MRI has moderately better diagnostic accuracy over 1.5T.
– Provocative positioning during scanning may also enhance visualization of tears.
– High signal extending anterior and posterior to the biceps anchor insertion is the hallmark of SLAP tears.
– Specific criteria include laterally curved or multiple linear high signals in the superior labrum on coronal images.
– Full-thickness detachments, paralabral cysts, and wide separation between labrum and glenoid suggest tears.
– A recent systematic review showed MR arthrography has higher sensitivity for SLAP tears than standard MRI, but similar specificity.
– 3T MRI was moderately more accurate than 1.5T, with or without contrast.
– Overall diagnostic performance remains imperfect, emphasizing the need for correlation with clinical findings.
– Imaging, especially MR arthrography, can assist with identifying SLAP tears but findings must be interpreted in clinical context.
– Diagnostic accuracy continues to improve with technical advances like higher field strength MRI.
– Further research on optimizing imaging protocols is warranted to enhance non-invasive diagnosis of these injuries.
In summary, this review covers important concepts in MRI diagnosis of SLAP tears, which requires recognizing normal variants and characteristic imaging patterns. While imaging accuracy is imperfect, MR arthrography and 3T MRI assist diagnosis. However, correlation with clinical evaluation remains critical to guide management.