title: Time-resolved magnetic resonance angiography as a noninvasive method to characterize endoleaks: initial results compared with conventional angiography.
abstract: OBJECTIVE
  Several types of endoleaks have been described, each with different methods of treatment. Conventional arteriography is widely regarded as the gold standard for the classification of endoleaks. Recently, faster magnetic resonance gradients have allowed for rapid data acquisition and review of vascular studies as a real-time continuous angiogram (time resolved magnetic resonance angiography [TR-MRA]). This study was performed to compare the findings of TR-MRA with conventional angiography for the characterization of endoleaks.
  
  
  METHODS
  Between June 2002 and June 2003, 12 patients with documented endoleaks following endovascular repair of aortic aneurysms (10 abdominal and two thoracic) underwent TR-MRA to identify and characterize the endoleak. All patients had nitinol-based aortic stent grafts. MRA was performed on a 1.5-Tesla magnet (Sonata class; Siemens Medical Systems, Iselin, NJ). The TR-MRA studies were reviewed under continuous observation as a "cine MR angiogram." These MRA data sets were used to classify the endoleaks into types 1 through 3. The patients underwent conventional angiography following the MRA to confirm the findings and to plan treatment. The MRA findings were compared with the findings made at conventional arteriography.
  
  
  RESULTS
  TR-MRA identified seven patients with type 1 leaks, including four proximal and three distal. Four patients had type 2 leaks, including two arising from the inferior mesenteric artery and two from an iliolumbar artery. One patient had a type 3 leak. Conventional angiography confirmed the type of endoleak in all 12 patients.
  
  
  CONCLUSIONS
  These initial results demonstrate TR-MRA to be an effective noninvasive method for classifying endoleaks. This technique may allow for screening of patients with endoleaks to identify those requiring urgent repair.
authors.affiliation: Department of Interventional Radiology, Mount Sinai Medical Center, One Gustave L. Levy Place, Box 1234, New York, NY 10029, USA. Robert.Lookstein@mssm.edu
authors.forename: Robert A
authors.initials: RA
authors.lastname: Lookstein
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Goldman
authors.forename: Lev
authors.initials: L
authors.lastname: Pukin
authors.forename: Michael L
authors.initials: ML
authors.lastname: Marin
mesh_terms: D015901:Angiography, Digital Subtraction; D001014:Aortic Aneurysm / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000601:surgery*; D001027:Aortography; D001807:Blood Vessel Prosthesis / Q000009:adverse effects*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects*; D006801:Humans; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography; D011183:Postoperative Complications / Q000175:diagnosis*; D015607:Stents / Q000009:adverse effects*; D014057:Tomography, X-Ray Computed