title: US of the Knee: Scanning Techniques, Pitfalls, and Pathologic Conditions.
abstract: Pain and other disorders of the knee are a common presenting complaint in the ambulatory setting. Although the cornerstones of imaging evaluation of the knee are radiographs and magnetic resonance (MR) imaging, ultrasonography (US) is less expensive than MR imaging, easily available, and of comparable accuracy in the evaluation of certain pathologic conditions of the knee. The benefits of US include portability, low cost, high spatial resolution, dynamic imaging, and ability to guide percutaneous interventions when indicated. US also allows direct patient contact, facilitating immediate clinical correlation and the ability to compare with the contralateral knee. US evaluation of the knee can be targeted to a specific region on the basis of the complaint or be a comprehensive review. For comprehensive evaluation, the knee is divided into anterior, medial, lateral, and posterior compartments for structured evaluation of the tendons, ligaments, joint space, osseous structures, as well as peripheral nerves and vasculature. US is particularly well suited for evaluating injuries of the quadriceps and patellar tendons, injuries of the medial and lateral collateral ligaments, joint effusions, and fluid collections around the knee. There is additional utility in evaluation of the distal hamstrings tendons, the iliotibial tract, the superficial patellar cortex, the common peroneal nerve, the popliteal vessels, and juxta-articular cystic collections including Baker cyst. In-depth appreciation of relevant sonographic anatomy, common pathologic conditions, knowledge of important pitfalls, and mastery of US technique will allow one to effectively use this powerful bedside tool for the evaluation of a wide variety of knee disorders.©RSNA, 2016.
authors.affiliation: From the Department of Radiology, Division of Musculoskeletal Imaging, University of Michigan Health System, 2910 S Taubman Center, SPC 5326, 1500 E Medical Center Dr, Ann Arbor, MI 48109.
authors.forename: Timothy I
authors.identifier: http://orcid.org/0000-0001-5056-681X
authors.initials: TI
authors.lastname: Alves
authors.affiliation: From the Department of Radiology, Division of Musculoskeletal Imaging, University of Michigan Health System, 2910 S Taubman Center, SPC 5326, 1500 E Medical Center Dr, Ann Arbor, MI 48109.
authors.forename: Gandikota
authors.initials: G
authors.lastname: Girish
authors.affiliation: From the Department of Radiology, Division of Musculoskeletal Imaging, University of Michigan Health System, 2910 S Taubman Center, SPC 5326, 1500 E Medical Center Dr, Ann Arbor, MI 48109.
authors.forename: Monica
authors.initials: M
authors.lastname: Kalume Brigido
authors.affiliation: From the Department of Radiology, Division of Musculoskeletal Imaging, University of Michigan Health System, 2910 S Taubman Center, SPC 5326, 1500 E Medical Center Dr, Ann Arbor, MI 48109.
authors.forename: Jon A
authors.initials: JA
authors.lastname: Jacobson
mesh_terms: D003937:Diagnosis, Differential; D003951:Diagnostic Errors / Q000517:prevention & control*; D019317:Evidence-Based Medicine; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007592:Joint Diseases / Q000000981:diagnostic imaging*; D007718:Knee Injuries / Q000000981:diagnostic imaging*; D007719:Knee Joint / Q000000981:diagnostic imaging*; D056888:Patient Positioning / Q000379:methods; D014463:Ultrasonography / Q000379:methods*