MRI Musculotendinous Junction Cysts and Delaminating Rotator Cuff Tears.
Musculotendinous junction cysts can be seen in the rotator cuff tendons, mostly in Supraspinatus and less commonly in infraspinatus.
- MTJ cysts area result of an underlying articular surface delaminating tear.
- The tear extends through the tendon and when it gets to the MTJ, is arrested.
- Fluid keeps accumulating in the tear which wells up at the MTJ to form a cyst.
Centered at the MTJ, but if large can extend into the tendon and muscle.
- Can be single or multiple cysts (Pink arrows).
- Usually not septated and no enhancement.
- May see connecting delaminating tear (Blue arrows).
Here is what to look for when assessing MTJ cysts.
- Location (which tendon) of cyst/s.
- Size of cyst/s.
- A delaminating tear extending to the cyst.
We look at musculotendinous junction cysts and delaminating tears in more detail in the MRI Shoulder Mini Fellowship. Click on the image below.