title: Incidence of actionable findings on contrast enhanced magnetic resonance angiography ordered for pulmonary embolism evaluation.
abstract: OBJECTIVE
  To determine the incidence of actionable findings on contrast-enhanced magnetic resonance angiography (MRA) scans performed for the primary diagnosis of pulmonary embolism (PE).
  
  
  METHODS
  This was a HIPAA-compliant and IRB-approved single center, retrospective study of consecutive series of patients evaluated with contrast-enhanced MRA for PE. The final radiology report of each MRA was reviewed. All technically adequate negative exams were included in the analysis. The findings were divided into three types: those requiring further action (actionable-Type 1) those not requiring follow-up (non-actionable-Type 2) and normal exams. We compared our results with the literature regarding the use of computed tomographic angiography (CTA) in this scenario using Fisher's exact test.
  
  
  RESULTS
  580 MRA scans for PE were performed. There were 561/580 (97%) technically adequate exams. Of these, 514/580 (89%) were negative and 47/580 (8%) were positive for PE. In the PE negative group of 514 exams, Type 1 findings were identified in 85/514 (17%), 188/514 (36%) cases were Type 2 and 241/514 (47.0%) were Type 3. There was no significant difference between the incidence of Type 1 and the combination of Type 2 and Type 3 findings on MRA and the reported incidence of actionable findings derived from CTA negative exams for PE (p<0.5).
  
  
  CONCLUSIONS
  MRA as a first-line test for PE can identify actionable findings in those patients without PE, with an incidence similar to that reported in the literature for CTA.
authors.affiliation: Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States. Electronic address: mschiebler@uwhealth.org.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Schiebler
authors.affiliation: Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Department of Radiology, University of Washington School of Medicine, Seattle, WA, United States.
authors.forename: Jitesh
authors.initials: J
authors.lastname: Ahuja
authors.affiliation: Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Department of Emergency Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Repplinger
authors.affiliation: Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: François
authors.affiliation: Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States.
authors.forename: Karl K
authors.initials: KK
authors.lastname: Vigen
authors.affiliation: Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Department of Biomedical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Grist
authors.affiliation: Department of Emergency Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States.
authors.forename: Azita G
authors.initials: AG
authors.lastname: Hamedani
authors.affiliation: Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Department of Emergency Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Department of Biomedical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States.
authors.forename: Scott B
authors.initials: SB
authors.lastname: Reeder
authors.affiliation: Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States.
authors.forename: Scott K
authors.initials: SK
authors.lastname: Nagle
mesh_terms: D061605:Administration, Intravenous; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001014:Aortic Aneurysm / Q000000981:diagnostic imaging; D001018:Aortic Diseases / Q000000981:diagnostic imaging; D002648:Child; D003287:Contrast Media / Q000008:administration & dosage; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D015994:Incidence; D033162:Incidental Findings; D018810:Magnetic Resonance Angiography / Q000145:classification / Q000706:statistics & numerical data*; D008297:Male; D008536:Meglumine / Q000008:administration & dosage / Q000031:analogs & derivatives; D008875:Middle Aged; D009942:Organometallic Compounds / Q000008:administration & dosage; D010490:Pericardial Effusion / Q000000981:diagnostic imaging; D010996:Pleural Effusion / Q000000981:diagnostic imaging; D011014:Pneumonia / Q000000981:diagnostic imaging; D011030:Pneumothorax / Q000000981:diagnostic imaging; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D013899:Thoracic Neoplasms / Q000000981:diagnostic imaging; D055815:Young Adult
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine
keywords: Ancillary findings; Computed tomography angiography; Magnetic resonance angiography; Non-thrombotic findings; Pulmonary embolism