title: The prevalence of cervical ribs in Enugu, Nigeria.
abstract: BACKGROUND
  Cervical rib is an important cause of nontraumatic thoracic outlet neurovascular compression. This study was undertaken as there is no known documented report on its prevalence in the study environment.
  
  
  OBJECTIVE
  To evaluate the prevalence of cervical ribs and its variation with sex and age among patients presenting at radiological facilities for a chest radiograph.
  
  
  METHODS
  Retrospective evaluation of plain posterior-anterior view chest radiographs done in radiological facilities in Enugu, Southeast, Nigeria.
  
  
  METHODS
  Evaluated in this study were all 6571 chest radiographs consecutively obtained between 2009 and 2012 in three randomly selected radiological facilities in Enugu.
  
  
  METHODS
  SPSS version 17 software was used in data analysis. Chi-square and student t-tests were used to test for the significance of findings at 95% confidence level.
  
  
  RESULTS
  This study reports the overall prevalence of cervical ribs as 48 (0.7%) with a significantly higher rate in females 43 (1.1%) when compared to males 5 (0.2%) (P = 0.000). In 27 (0.4%) cases, the cervical ribs were bilateral; whereas in 21 (0.3%) cases, they were unilateral with 8 (0.1%) on the left and 13 (0.2%) on the right. There was no age-related variability with prevalence (P = -0.813).
  
  
  CONCLUSIONS
  The prevalence of cervical rib in the study population is low and within the known range as seen in other geographical regions of Nigeria.
authors.affiliation: Department of Radiation Medicine, College of Medicine, University of Nigeria, Enugu Campus, Enugu State, Nigeria.
authors.forename: S N
authors.initials: SN
authors.lastname: Ezeofor
authors.affiliation: Department of Radiation Medicine, College of Medicine, University of Nigeria, Enugu Campus, Enugu State, Nigeria.
authors.forename: N R
authors.initials: NR
authors.lastname: Njeze
authors.affiliation: Department of Community Medicine, College of Medicine, University of Nigeria, Enugu Campus, Enugu State, Nigeria.
authors.forename: M N
authors.initials: MN
authors.lastname: Aghaji
authors.affiliation: Department of Radiation Medicine, College of Medicine, University of Nigeria, Enugu Campus, Enugu State, Nigeria.
authors.forename: A C
authors.initials: AC
authors.lastname: Onuh
authors.affiliation: Department of Anatomy, College of Medicine, University of Nigeria, Enugu Campus, Enugu State, Nigeria.
authors.forename: E N
authors.initials: EN
authors.lastname: Obikili
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D057070:Cervical Rib / Q000000981:diagnostic imaging; D002573:Cervical Rib Syndrome / Q000000981:diagnostic imaging / Q000453:epidemiology*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009549:Nigeria / Q000453:epidemiology; D015995:Prevalence; D013902:Radiography, Thoracic; D012189:Retrospective Studies; D017678:Sex Distribution; D055815:Young Adult