title: Wide field of view CT and acromioclavicular joint instability: A technical innovation.
abstract: A 21-year-old female with a traumatic shoulder injury is investigated and managed for symptoms relating to this injury. Pathology at the acromioclavicular joint is detected clinically; however, clinical examination and multiple imaging modalities do not reach a unified diagnosis on the grading of this acromioclavicular joint injury. When management appropriate to that suggested injury grading fail to help the patient's symptoms, further investigation methods were utilised. Wide field of view, dynamic CT (4D CT) is conducted on the patient's affected shoulder using a 320 × 0.5 mm detector multislice CT. Scans were conducted with a static table as the patient completed three movements of the affected shoulder. Capturing multiple data sets per second over a z-axis of 16 cm, measurements of the acromioclavicular joint were made, to show dynamic changes at the joint. Acromioclavicular (AC) joint translations were witnessed in three planes (a previously unrecognised pathology in the grading of acromioclavicular joint injuries). Translation in multiple planes was also not evident on careful clinical examination of this patient. AC joint width, anterior-posterior translation, superior-inferior translation and coracoclavicular width were measured with planar reconstructions while volume-rendered images and dynamic sequences aiding visual understanding of the pathology. Wide field of view dynamic CT (4D CT) is an accurate and quick modality to diagnose complex acromioclavicular joint injury. It provides dynamic information that no other modality can; 4D CT shows future benefits for clinical approach to diagnosis and management of acromioclavicular joint injury, and other musculoskeletal pathologies.
authors.affiliation: Department of Orthopaedic Surgery, Dandenong Hospital, Melbourne, Victoria, Australia.
authors.forename: David R
authors.initials: DR
authors.lastname: Dyer
authors.affiliation: Department of Diagnostic Imaging, Monash Medical Centre, Melbourne, Victoria, Australia.
authors.forename: John M
authors.initials: JM
authors.lastname: Troupis
authors.affiliation: Department of Orthopaedic Surgery, The Alfred Hospital, Melbourne, Victoria, Australia.
authors.forename: Afshin
authors.initials: A
authors.lastname: Kamali Moaveni
mesh_terms: D000173:Acromioclavicular Joint / Q000000981:diagnostic imaging* / Q000293:injuries*; D000328:Adult; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging*; D061330:Multidetector Computed Tomography / Q000379:methods*; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: 4D CT; acromioclavicular joint; acromioclavicular joint instability; musculoskeletal imaging; wide field CT