title: Incidence of elbow injuries in adolescent baseball players: screening by a low field magnetic resonance imaging system specialized for small joints.
abstract: OBJECTIVE
  The aim of this preliminary study was to examine the capability of screening for elbow injuries induced by baseball using a low field small joint MRI system.
  
  
  METHODS
  Sixty-two players in the 4th-6th elementary school grades, with ages ranging from 9 to 12 years, participated in this study. Screening for elbow injuries was performed using a low-magnetic-field (0.2-T) magnetic resonance imaging (MRI) system designed for examinations of small joints of the extremities. Gradient-echo coronal, sagittal, and short-tau inversion recovery (STIR) coronal images of the dominant arm used for pitching were obtained to identify medial collateral ligament (MCL) injuries with or without avulsion fracture and osteochondritis dissecans.
  
  
  RESULTS
  All 62 examinations were performed successfully, with 26 players (41.9 %) showing positive findings, all being confined to the MCL. No child showed bone damage. All criteria in the MRI evaluation of injuries showed high agreement rates and kappa values between two radiologists.
  
  
  CONCLUSIONS
  Screening for early detection of elbow injuries in junior Japanese baseball players can be successfully performed using a low-field MRI system specialized for small joints. The percentage of MCL injury without avulsion fracture was unexpectedly high (41.9 %).
authors: Institute of Clinical Medicine Department of Diagnostic and Interventional Radiology, University of Tsukuba, 2-1-1 Amakubo, Tsukuba, Ibaraki, 305-8576, Japan. yokamoto@md.tsukuba.ac.jp.
authors: Yoshikazu
authors: Y
authors: Okamoto
authors: Graduate Program of Comprehensive Human Science, Doctor Program in Sports Medicine, University of Tsukuba, Tsukuba, Japan.
authors: Kiyoshi
authors: K
authors: Maehara
authors: Graduate Program of Comprehensive Human Science, Doctor Program in Coaching Science, University of Tsukuba, Tsukuba, Japan.
authors: Tetsuya
authors: T
authors: Kanahori
authors: Institute of Clinical Medicine Department of Diagnostic and Interventional Radiology, University of Tsukuba, 2-1-1 Amakubo, Tsukuba, Ibaraki, 305-8576, Japan.
authors: Takashi
authors: T
authors: Hiyama
authors: Graduate Program of Comprehensive Human Science, Doctor Program in Coaching Science, University of Tsukuba, Tsukuba, Japan.
authors: Takashi
authors: T
authors: Kawamura
authors: Institute of Clinical Medicine Department of Diagnostic and Interventional Radiology, University of Tsukuba, 2-1-1 Amakubo, Tsukuba, Ibaraki, 305-8576, Japan.
authors: Manabu
authors: M
authors: Minami
mesh_terms: D001484:Baseball / Q000293:injuries*; D002648:Child; D004551:Elbow Joint / Q000000981:diagnostic imaging*; D006801:Humans; D015994:Incidence; D008279:Magnetic Resonance Imaging; D008297:Male; D015203:Reproducibility of Results; D000092464:Elbow Injuries
keywords: Baseball; Elbow injury; Low magnetic field; Medial collateral ligament; Overuse; Screening