MR imaging features of paralabral ganglion cyst of the shoulder Poster No.: C-1482 Congress: ECR 2016 Type: Educational Exhibit Authors: M. Bartocci, C. Dell'atti, E. Federici, D. Beomonte Zobel, V. Martinelli, N. Magarelli, L. Bonomo; Rome/IT Keywords: DOI: Diagnostic procedure, MR, Musculoskeletal joint, Cysts 10.1594/ecr2016/C-1482 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 9
Learning objectives 1. Describe the epidemiology and physiopathology of paralabral ganglion cysts of the shoulder, as well as the clinical signs and current treatments for these pathological conditions. 2. Explain and illustrate the presentation of paralabral ganglion cysts of the shoulder and how we can visualize them at magnetic resonance (MR) imaging. Background 1. EPIDEMIOLOGY: Paralabral ganglion cysts of the shoulder can be observed in 2-4% of the general population. The highest incidence of cases is between III and IV decade of life and a male preponderance is recorded. 2. PRESENTATION: The paralabral ganglion cysts are most frequently reported along the posterior and superior aspects of the glenohumeral joint and are uncommon anteriorly and inferiorly to the joint. 3. PATHOPHYSIOLOGY: The pathogenesis is uncertain. It is believed that trauma results in tearing of the capsulolabral complex with synovial fluid forced into the tissues, creating a one-wayvalve effect. 4. CLINICAL PRESENTATION: The major signs and symptoms which these patients may present are: Shoulder pain with weakness of abduction and external rotation due to entrapment or compression of the nerve, i.e. suprascapular or axillary nerve. Chronic shoulder pain. Page 2 of 9
However, frequently paralabral ganglion cysts are incidentally diagnosed in imaging studies carried out by other cause. 5. TREATMENT: The presence of specific symptoms, i.e. nerve compression, is an indication for surgery that usually consists in decompression of ganglion cyst and labral repair with arthroscopic approach. In the absence of any specific symptom, i.e. nerve compression, the presence of a ganglion cyst is not an absolute indication for surgery. In those patients with a more common shoulder diagnosis, paralabral ganglion cysts should be considered incidental findings until the more common diagnosis has been treated. However, in the absence of other more clearly identifiable shoulder pathologic conditions, surgical resection of the cyst and labral repair should be considered in those patients who fit a specific profile. The profile includes patients with symptoms of pain on elevation, pain at rest and failure of conservative measures like nonsteroidal anti-inflammatory drugs and physical therapy. Findings and procedure details 1. MR IMAGING FINDINGS The best imaging technique for the diagnosis of paralabral ganglion cysts of the shoulder is MR imaging, which may show the following features (Fig. 1-3): Hyperintense T2-weighted cystic/septated masses arising from or adjacent to the labrum or capsule, most commonly from the posterior superior labrum. Ganglion cysts demonstrate a thin rim and may have thin internal septa, both of which may enhance after intravenous gadolinium administration, with a lack of central enhancement otherwise. High T2-weighted signal in the muscles of the shoulder indicates acute/subacute denervation, and atrophy/fatty change indicates chronic denervation. Ganglion cysts are the result of labral tears (occur in 3% to 5% of labral tears), which may be seen as a hyperintense linear defect or avulsion of the labrum, best seen on arthro-mr imaging. Paralabral ganglion cysts may fill with articular contrast. 2. MRI PROTOCOL In our institution, the standard imaging protocol includes T1 and T2-weighted FSE and STIR or DP-weighted fat-saturated FSE images, in three orthogonal planes. Page 3 of 9
Arthro-MR imaging can be eventually performed in a second step, using T1 and T2- weighted fat-saturated FSE images, in three orthogonal planes, after injection of MR arthrogram solution. MR arthrogram solution is a dilute solution of gadolinium that is used in arthro-mr imaging for injection into the joint prior to imaging. The joint injection is performed under fluoroscopic guidance. A number of recipes are used but a simple approach to preparing 20ml of solution is as follows: 10 ml normal saline; 0.1 ml gadolinium; 10 ml non-ionic iodinated contrast. The amount of contrast used will depend on the joint. Images for this section: Page 4 of 9
Page 5 of 9
Fig. 1: A. T2-weighted FSE image on coronal plane; B. T1-weighted FSE image on coronal plane. At MR imaging, paralabral ganglion cyst appears as hyperintense T2- weighted (white arrow) and hypointense T1-weighted (yellow arrow) cystic mass located at spinoglenoid notch, adjacent to the posterior superior labrum. Department Bioimaging and Radiological Sciences, Policlinico Gemelli Hospital - Rome/IT Fig. 2: T2-weighted FSE image on sagittal plane shows paralabral ganglion cysts with a thin rim and thin internal septa. Department Bioimaging and Radiological Sciences, Policlinico Gemelli Hospital - Rome/IT Page 6 of 9
Page 7 of 9
Fig. 3: A. T1 weighted fat-saturated FSE images on sagittal plane at arthro-mr imaging. B. T1 weighted fat-saturated FSE images on axial plane at arthro-mr imaging. Labral tear appears as hyperintense linear defect of the labrum (yellow arrows); after injection of MR arthrogram solution paralabral ganglion cyst fills with articular contrast. Department Bioimaging and Radiological Sciences, Policlinico Gemelli Hospital - Rome/IT Page 8 of 9
Conclusion Radiologists should be familiar with MR imaging features of paralabral ganglion cysts, allowing early diagnosis and treatment of these conditions that are a uncommon cause of chronic shoulder pain. Personal information References 1) Piatt BE et al. Clinical evaluation and treatment of spinoglenoid notch ganglion cysts. J Shoulder Elbow Surg 2002 Nov-Dec;11(6):600-4. 2) Lee BC et al. Suprascapular nerve neuropathy secondary to spinoglenoid notch ganglion cyst: case reports and review ofliterature. Ann Acad Med Singapore 2007 Dec;36(12):1032-5. 3) Bermejo A et al. MR imaging in the evaluation of cystic-appearing soft-tissue masses of the extremities. Radiographics 2013 May;33(3):833-55. doi: 10.1148/rg.333115062. 4) Ji JH et al. Inferior paralabral ganglion cyst of the shoulder with labral tear -- a rare cause of shoulder pain. Orthop Traumatol Surg Res 2012 Apr;98(2):193-8. doi: 10.1016/ j.otsr.2011.09.020 Page 9 of 9