title: MR angiography can guide ED management of suspected acute aortic dissection.
abstract: BACKGROUND
  Aortic dissection is typically evaluated with computed tomography angiography (CTA). However, the feasibility of using magnetic resonance angiography (MRA) in the ED is unclear. This study examined the indications and outcomes of MRA in suspected aortic dissection evaluation in the ED.
  
  
  METHODS
  An IRB approved review identified patients who underwent MRA in the ED for acute thoracic aortic dissection from January 2010 to June 2016. Demographics, clinical assessment, CTA contraindications, outcomes, and ED disposition were analyzed.
  
  
  RESULTS
  50 MRAs were ordered for suspected thoracic aortic dissection. 21 (42%) for iodinated contrast allergy, 21 (42%) for renal insufficiency, 2 (4%) due to both, 2 (4%) to spare ionizing radiation, 2 (4%) for further work-up after CTA, and 2 (4%) due to prior contrast enhanced CT within 24h. Median ED arrival to MRA completion time was 311min. 42 studies were fully diagnostic; 7 were limited. One patient could not tolerate the examination. 49 MRAs were completed: 2 (4%) patients had acute dissection on MRA and 47 (96%) had negative exams. 17 (35%) received gadolinium. 18 (37%) patients were discharged home from the ED with a median length of stay of 643min. 2 (4%) were admitted for acute dissection seen on MRA and 29 (59%) for further evaluation.
  
  
  CONCLUSIONS
  MRA has a clear role in the evaluation for acute thoracic aortic dissection in the ED in patients with contraindications to CTA, and can guide management and facilitate safe discharge to home.
authors.affiliation: Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Gary X
authors.initials: GX
authors.lastname: Wang
authors.affiliation: Division of Cardiovascular Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Sandeep S
authors.initials: SS
authors.lastname: Hedgire
authors.affiliation: Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Thang Q
authors.initials: TQ
authors.lastname: Le
authors.affiliation: Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Sonis
authors.affiliation: Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Yun
authors.affiliation: Division of Emergency Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Lev
authors.affiliation: Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Ali S
authors.initials: AS
authors.lastname: Raja
authors.affiliation: Division of Cardiovascular Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA; Division of Emergency Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA. Electronic address: aprabhakar@mgh.harvard.edu.
authors.forename: Anand M
authors.initials: AM
authors.lastname: Prabhakar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000784:Aortic Dissection / Q000000981:diagnostic imaging*; D017545:Aortic Aneurysm, Thoracic / Q000000981:diagnostic imaging*; D000072226:Computed Tomography Angiography; D000075202:Contraindications; D003287:Contrast Media / Q000009:adverse effects; D004342:Drug Hypersensitivity / Q000209:etiology; D004636:Emergency Service, Hospital; D005240:Feasibility Studies; D005260:Female; D005682:Gadolinium; D019786:Gadolinium DTPA; D006801:Humans; D007455:Iodine / Q000009:adverse effects; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D051436:Renal Insufficiency, Chronic; D012189:Retrospective Studies; D013997:Time Factors; D055815:Young Adult
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D007455:Iodine; D005682:Gadolinium; D019786:Gadolinium DTPA; C109932:gadofosveset trisodium
keywords: ACR Appropriateness Criteria; Acute aortic syndrome; Aortic dissection; Emergency radiology; Magnetic resonance angiography