Conventional MRI, supplemented with MR arthrography, can accurately diagnose injuries sustained by the throwing athlete, such as rotator cuff tears and tendinosis, as well as labral and capsuloligamentous pathologic conditions [2-4]. MR arthrography requires the intra-articular injection of 12 mL or more of a dilute gadolinium solution (1:250 or 2 mmol/L) to distend the joint capsule and outline the labral and articular surface tears of the rotator cuff . At a concentration of 2 mmol/L, the paramagnetic effect of gadolinium and hence its signal intensity on Tl-weighted images in a 1.5 Telsa magnetic field are optimal . Indirect MR arthrography with intravenous administration of gadolinium may also be performed; this is dependent on diffusion of contrast into the joint space from the highly vascular synovium. Though it is less invasive than direct MR arthrography, lack of joint distention makes this technique less useful for labral tears .
Imaging of the shoulder may be performed with the arm in a neutral position or may be performed with the arm in the abducted and externally rotated (ABER) position by having the patient place the hand behind the head. The ABER position mimics the late cocking phase of the throw, stretches the anterior capsuloligamentous structures, in particular the anterior band of the inferior glenohumeral ligament, and allows better visualization of the postero-superior aspect of the labrum and the undersurface of the supraspinatus tendon [8-12]. If the patient is unable to tolerate the ABER position, full external rotation of the conventionally positioned arm will similarly stretch the anterior capsule [12,13], but this position does not simulate the cocking phase.
Was this article helpful?
You can have significantly bigger arms in only 31 days. How much bigger? That depends on a lot of factors. You werent able to select your parents so youre stuck with your genetic potential to build muscles. You may have a good potential or you may be like may of the rest of us who have averages Potential. Download this great free ebook and start learns how to build your muscles up.