Yes, the MRI would show the tear and be the best diagnostic test, that been said there is no real need for an expensive test as the drop-arm test is highly sensitive.dude..i think MRI is definitive Dx for rotator cuff tear....
the reason it's used for rotator cuff tendinitis is to differentiate from rotator cuff tear prior to arthroscopic surgery..
please,clarify me if you have any other explanation too...thanks
Arthrogram is much accurate,then MRI.Rotator Cuff Impingement/Tendonitis: Patient complains of shoulder pain aggrevated by activities like reaching or lifting arm over head. Common in middle aged; repeated activities overhead are the cause. Confirmed by "Neer Test" (passive motion of arm above head). Pain or guarding during the test confirms impingement. To distinguish from other, inject lidocaine; if improvement of range of motion and pain relief acheived, diagnosis confirmed. MRI is definitive test for dx.
Rotator Cuff Tear: chronic impingement and tendonitis or trauma. Symptoms same as above but no improvement seen with lidocaine injection. Weakness of the shoulder also seen. Look for a history of falling on outstretched hands. On Physical Exam: when patient told to abduct arms over head and told to bring down slowly; the affected arm drops rapidly at midpoint of its descent. Drop arm test is diagnostic.
Adhesive Capsulitis: cant lift arm overhead even after lidocaine injection.
Subacromial Bursitis: lies between acromion and tendon of supraspinatus muscle. Inflammation of subacromion bursitis occurs w chronic microtrauma to supraspinatus muscle tendon. This is also caused by overhead work and repeated overhead movements of arm during work or sporting activities (tennis serve). Tendon is compressed between acromion and the humeral head with its vascular supply temporarily compromised.
on P/E: there is pain with active ROM of the shoulder, tenderness in the shoulder with active range of motion of the shoulder, tenderness in the shoulder with arm internally rotated.
Dislocated Shoulder: head of humerus rotates out of the glenoid cavity
Separated Shoulder: clavicle separates from acromion and coracoid process
Hope this helps somewhat. My notes from UW, Kaplan and a bit of First Aid I guess.