Intrasubstance rotator cuff tear
Intrasubstance tears are also known as concealed interstitial delaminations (CID) .
According to cadaver studies they are the most common form of partial-thickness rotator cuff tear.
Intrasubstance tears are confined to the tendon substance and bursal as well as articular side appear normal at arthroscopy .
Intrasubstance tears are most commonly found in the posterior supraspinatus tendon .
Intrasubstance rotator cuff tears are difficult to detect.
On ultrasound, a focal hypoechoic or anechoic slit of the rotator cuff within the tendon substance might be seen.
A typical finding is a linear non-transmural intrasubstance slit of fluid signal intensity of the rotator cuff on fat-saturated T2- weighted or intermediate-weighted images with intact articular-sided and bursal-sided fibers.
CT arthrography will not depict an intrasubstance rotator cuff tear since per definition it is concealed. MR arthrography should not have any additional advantage over MRI unless to prove the suspected tear is not a partial articular tear with intratendinous extension or PAINT lesion.