title: Magnetic Resonance Imaging with a Weak Albumin Binding Contrast Agent can Reveal Additional Endoleaks in Patients with an Enlarging Aneurysm after EVAR.
abstract: OBJECTIVE
  To examine the additional diagnostic value of magnetic resonance imaging (MRI) after administration of a weak albumin binding contrast agent in post-endovascular aneurysm repair (EVAR) patients with aneurysm growth with no or uncertain endoleak after computed tomography angiography (CTA).
  
  
  METHODS
  This was a prospective diagnostic cross sectional study carried out between April 2011 and August 2013. MRI was performed in all patients with aneurysm growth≥5 mm after EVAR implantation and no or uncertain endoleak on CTA, or the inability, on CTA, to identify the source of a visible endoleak. All MRI scans were performed on a 1.5 T clinical MRI scanner after administration of a weak albumin binding contrast agent. The presence of endoleaks was assessed by visually comparing pre- and post-contrast T1-weighted images with fat suppression. Post-contrast images were acquired 5 and 15 minutes after contrast administration.
  
  
  RESULTS
  Twenty-nine patients (26 men; 90%) with a median age of 74 years (interquartile range [IQR] 67-76) were included. The median interval between EVAR and MRI was 39 months (IQR 20-50). The median increase in maximum aneurysm diameter during total follow up after EVAR was 11 mm (IQR 6-17). At CTA, 16 patients (55%) had no detectable endoleak, five patients (17%) had suspected but uncertain endoleak, and eight patients had a definite endoleak (28%). On the post-contrast MRI images, endoleak was observed in 24 patients (83%). In all patients with uncertain endoleak on CTA, endoleak was detected with MRI. For type II endoleaks, feeding vessels were detected in 22/23 patients (96%) and these were all, except one, lumbar arteries.
  
  
  CONCLUSIONS
  In patients with enlarging aneurysms of unknown origin after EVAR, MRI with a weak albumin binding contrast agent has additional value for both the detection and determination of the origin of the endoleak.
authors.affiliation: Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands; Department of Radiology, Gelre Hospitals, Apeldoorn, The Netherlands. Electronic address: j.habets@umcutrecht.nl.
authors.forename: J
authors.initials: J
authors.lastname: Habets
authors.affiliation: Department of Vascular Surgery, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: H J A
authors.initials: HJ
authors.lastname: Zandvoort
authors.affiliation: Department of Vascular Surgery, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: F L
authors.initials: FL
authors.lastname: Moll
authors.affiliation: Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: L W
authors.initials: LW
authors.lastname: Bartels
authors.affiliation: Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: E P A
authors.initials: EP
authors.lastname: Vonken
authors.affiliation: Department of Vascular Surgery, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: J A
authors.initials: JA
authors.lastname: van Herwaarden
authors.affiliation: Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: T
authors.initials: T
authors.lastname: Leiner
mesh_terms: D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis / Q000601:surgery*; D001027:Aortography / Q000379:methods; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects*; D003287:Contrast Media / Q000378:metabolism; D003430:Cross-Sectional Studies; D057867:Endoleak / Q000097:blood / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy; D057510:Endovascular Procedures / Q000009:adverse effects*; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives* / Q000378:metabolism; D009942:Organometallic Compounds / Q000378:metabolism; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011485:Protein Binding; D012709:Serum Albumin / Q000378:metabolism*; D000075462:Serum Albumin, Human; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: C422455:ALB protein, human; D003287:Contrast Media; D009942:Organometallic Compounds; D012709:Serum Albumin; C064572:gadobenic acid; D008536:Meglumine; D000075462:Serum Albumin, Human
keywords: AAA; EVAR; Endoleak; Endotension; MRI