title: Subspecialty Virtual Impact Factors within a Dedicated Neuroimaging Journal.
abstract: OBJECTIVE
  The growing number of subspecialties within neuroradiology compete for pages in neuroradiology journals. We performed a bibliometric analysis of the American Journal of Neuroradiology to identify the virtual Impact Factor of different journal subsections and article topics.
  
  
  METHODS
  Original Research and Review Articles published in American Journal of Neuroradiology during 2010-2012 were evaluated. The journal section for each article was recorded, and the number of citations was evaluated by using the Web of Science database. Numbers of citations within the first 2 years after publication were evaluated, normalized to the 2013 journal Impact Factor (for American Journal of Neuroradiology, 3.675), and used to calculate a virtual Impact Factor for different journal subsections.
  
  
  RESULTS
  One thousand forty-nine Original Research and Review Articles were published during this time, which obtained an average of 6.59 citations each within their first 2 years after publication; 91.8% of articles obtained at least 1 citation. Expedited Publications had the greatest number of citations, averaging 43.7 citations each (virtual Impact Factor, 24.39), followed by Review Articles averaging 9.39 citations each (virtual Impact Factor 5.23). Virtual Impact Factors for other sections were the following: Interventional, 4.54; Brain, 3.70; Pediatrics, 2.91; Functional, 2.74; Head & Neck, 2.24; and Spine, 1.86. Virtual Impact Factors for article topics were the following: interventional, 4.75; functional/advanced, 3.79; brain, 3.66; pediatrics, 2.99; head and neck, 2.46; and spine, 2.32.
  
  
  CONCLUSIONS
  Citation patterns of Original Research and Review Articles in American Journal of Neuroradiology varied widely on the basis of subsections. Understanding the citation patterns of specific topics and subsections of a journal may aid authors and editors in evaluating the appropriate balance among various topics and allow authors to determine whether their articles are being cited at a level expected for similar ones in a journal.
authors.affiliation: From the Departments of Radiology (A.F.C.) Neurosurgery (A.F.C.) Ophthalmology (A.F.C.), University of Tennessee Health Science Center, Memphis, Tennessee Department of Radiology (A.F.C.), Le Bonheur Children's Hospital, Memphis, Tennessee achoudhri@uthsc.edu.
authors.forename: A F
authors.identifier: http://orcid.org/0000-0002-3154-6319
authors.initials: AF
authors.lastname: Choudhri
authors.affiliation: Department of Radiology (M.C.) University of North Carolina, Chapel Hill, North Carolina.
authors.forename: M
authors.identifier: http://orcid.org/0000-0003-2960-1064
authors.initials: M
authors.lastname: Castillo
mesh_terms: D015706:Bibliometrics; D006801:Humans; D055811:Journal Impact Factor; D059906:Neuroimaging; D010506:Periodicals as Topic; D012106:Research; D013038:Specialization