title: Automatic Classification of Free-Text Radiology Reports to Identify Limb Fractures using Machine Learning and the SNOMED CT Ontology.
abstract: OBJECTIVE
  To develop and evaluate machine learning techniques that identify limb fractures and other abnormalities (e.g. dislocations) from radiology reports.
  
  
  METHODS
  99 free-text reports of limb radiology examinations were acquired from an Australian public hospital. Two clinicians were employed to identify fractures and abnormalities from the reports; a third senior clinician resolved disagreements. These assessors found that, of the 99 reports, 48 referred to fractures or abnormalities of limb structures. Automated methods were then used to extract features from these reports that could be useful for their automatic classification. The Naive Bayes classification algorithm and two implementations of the support vector machine algorithm were formally evaluated using cross-fold validation over the 99 reports.
  
  
  RESULTS
  Results show that the Naive Bayes classifier accurately identifies fractures and other abnormalities from the radiology reports. These results were achieved when extracting stemmed token bigram and negation features, as well as using these features in combination with SNOMED CT concepts related to abnormalities and disorders. The latter feature has not been used in previous works that attempted classifying free-text radiology reports.
  
  
  CONCLUSIONS
  Automated classification methods have proven effective at identifying fractures and other abnormalities from radiology reports (F-Measure up to 92.31%). Key to the success of these techniques are features such as stemmed token bigrams, negations, and SNOMED CT concepts associated with morphologic abnormalities and disorders.
  
  
  CONCLUSIONS
  This investigation shows early promising results and future work will further validate and strengthen the proposed approaches.
authors.affiliation: The Australian e-Health Research Centre, Brisbane, Queensland, Australia;
authors.forename: Guido
authors.initials: G
authors.lastname: Zuccon
authors.forename: Amol S
authors.initials: AS
authors.lastname: Wagholikar
authors.forename: Anthony N
authors.initials: AN
authors.lastname: Nguyen
authors.forename: Luke
authors.initials: L
authors.lastname: Butt
authors.forename: Kevin
authors.initials: K
authors.lastname: Chu
authors.forename: Shane
authors.initials: S
authors.lastname: Martin
authors.forename: Jaimi
authors.initials: J
authors.lastname: Greenslade