Filippo Paolo Del Grande MD, Presenter: Institutional Grant, Siemens AG Shareholder, General Electric Company

John A. Carrino MD, MPH, Abstract Co-Author: Research Grant, Siemens AG Research Grant, Carestream Health, Inc Research Consultant, General Electric Company

To describe 3 Tesla MRI features of the elbow in asymptomatic professional baseball pitchers

Retrospective evaluation of 18 MRI of elbows in asymptomatic male professional baseball pitchers (mean age 23.1 years; age range 18 to 34 years old). Images were acquired on 3 Tesla MR-system using an eight channel phased array receiver coil. One musculoskeletal radiologist reviewed the MRI images for qualitative analysis (collateral ligaments, tendons, cartilage, bones, ulnar nerve, and joint fluid) and one radiologist for quantitative analysis (ligament and postero-lateral plica thickness).

Qualitative results The following abnormalities were identified. The anterior bundle of the UCL was considered thick in 72% (13/18) of subjects. 55% (10/18) had partial tears of the anterior UCL bundle, 60% (6/10) on the proximal attachment and 40% (4/10) on the distal attachment. Tendinopathy (tendinosis or partial tears) were present in 22% (4/18) for CFT, 33% (6/18) for CET and 44% (8/18) for triceps tendon. High grade cartilage lesions were identified in 22% (4/18); 2 in the ulno-humeral joint and 2 in the radiocapitellar joint. Osteophytes were present in 44% (8/18) in the ulno-humeral joint and in 33% (6/18) in the postero-medial joint space. 72% (13/18) subjects show a mild to moderate high signal intensity of the ulnar nerve and 33% (6/18) had flat deformity. 33% (6/18) show a mild joint effusion, two of them with intra-articular loose bodies. Quantitative evaluation The average thickness in mm were the following: anterior bundle UCL (4.9, SD ± 2.5), posterior bundle UCL (1.6, SD ±0.7), radial collateral ligament (2.2, SD± 0.9), LUCL (2.9, SD± 0.6) and annular ligament (0.9, SD± 0.3). The mean measurement of the postero-lateral plica was 4.9 x 2.6 x 3.1 (sagittal x craniocaudal x mediolateral).  

On 3 T MRI, asymptomatic pitchers show high prevalence of abnormalities of the anterior bundle of the UCL, of the triceps tendons, of the cartilage of the ulno-humeral joint and radio-capitellar joint, and of ulnar nerve. The anterior UCL bundle has an average thickening of 4.9 mm and the posterior bundle of 1.6 mm which are greater than the non-pitchers asymptomatic population.

The radiologist should be aware of the high prevalence of MRI abnormalities in asymptomatic baseball pitchers to establish positivity criteria for interpreting MRIs of symptomatic pitchers.

Del Grande, F, Carrino, J, 3 Tesla MR Imaging of the Elbow in Asymptomatic Professional Baseball Pitchers.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12030509.html