title: Automatic Classification of Ultrasound Screening Examinations of the Abdominal Aorta.
abstract: Our work facilitates the identification of veterans who may be at risk for abdominal aortic aneurysms (AAA) based on the 2007 mandate to screen all veteran patients that meet the screening criteria. The main research objective is to automatically index three clinical conditions: pertinent negative AAA, pertinent positive AAA, and visually unacceptable image exams. We developed and evaluated a ConText-based algorithm with the GATE (General Architecture for Text Engineering) development system to automatically classify 1402 ultrasound radiology reports for AAA screening. Using the results from JAPE (Java Annotation Pattern Engine) transducer rules, we developed a feature vector to classify the radiology reports with a decision table classifier. We found that ConText performed optimally on precision and recall for pertinent negative (0.99 (0.98-0.99), 0.99 (0.99-1.00)) and pertinent positive AAA detection (0.98 (0.95-1.00), 0.97 (0.92-1.00)), and respectably for determination of non-diagnostic image studies (0.85 (0.77-0.91), 0.96 (0.91-0.99)). In addition, our algorithm can determine the AAA size measurements for further characterization of abnormality. We developed and evaluated a regular expression based algorithm using GATE for determining the three contextual conditions: pertinent negative, pertinent positive, and non-diagnostic from radiology reports obtained for evaluating the presence or absence of abdominal aortic aneurysm. ConText performed very well at identifying the contextual features. Our study also discovered contextual trigger terms to detect sub-standard ultrasound image quality. Limitations of performance included unknown dictionary terms, complex sentences, and vague findings that were difficult to classify and properly code.
authors.affiliation: Department of Radiology, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA. Craig.Morioka@va.gov.|Medical Imaging Informatics, UCLA, Los Angeles, CA, USA. Craig.Morioka@va.gov.|Department of Radiology, UCLA, Los Angeles, CA, USA. Craig.Morioka@va.gov.
authors.forename: Craig
authors.initials: C
authors.lastname: Morioka
authors.affiliation: Medical Imaging Informatics, UCLA, Los Angeles, CA, USA.|Department of Radiology, UCLA, Los Angeles, CA, USA.
authors.forename: Frank
authors.initials: F
authors.lastname: Meng
authors.affiliation: Medical Imaging Informatics, UCLA, Los Angeles, CA, USA.|Department of Radiology, UCLA, Los Angeles, CA, USA.
authors.forename: Ricky
authors.initials: R
authors.lastname: Taira
authors.affiliation: Medical Imaging Informatics, UCLA, Los Angeles, CA, USA.|Department of Radiology, UCLA, Los Angeles, CA, USA.
authors.forename: James
authors.initials: J
authors.lastname: Sayre
authors.affiliation: Department of Radiology, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA.|Department of Radiology, UCLA, Los Angeles, CA, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Zimmerman
authors.affiliation: Department of Radiology, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA.|Department of Radiology, UCLA, Los Angeles, CA, USA.
authors.forename: David
authors.initials: D
authors.lastname: Ishimitsu
authors.affiliation: Department of Radiology, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA.|Department of Radiology, UCLA, Los Angeles, CA, USA.
authors.forename: Jimmy
authors.initials: J
authors.lastname: Huang
authors.affiliation: Department of Radiology, UCLA, Los Angeles, CA, USA.
authors.forename: Luyao
authors.initials: L
authors.lastname: Shen
authors.affiliation: Department of Radiology, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA.|Medical Imaging Informatics, UCLA, Los Angeles, CA, USA.|Department of Radiology, UCLA, Los Angeles, CA, USA.
authors.forename: Suzie
authors.initials: S
authors.lastname: El-Saden
mesh_terms: D000368:Aged; D000465:Algorithms; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging*; D017544:Aortic Aneurysm, Abdominal / Q000145:classification / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening; D012189:Retrospective Studies; D014463:Ultrasonography
keywords: Abdominal aortic aneurysm; Classification; Coding; Natural language processing