title: Series of Noncontrast Time-of-Flight Magnetic Resonance Angiographies to Identify Problems with Arteriovenous Fistula Maturation.
abstract: BACKGROUND
  Successful maturation of arteriovenous fistulas (AVFs) remains a challenge for those managing patients with end-stage renal disease. Time-of-flight magnetic resonance angiography (TOF-MR) can be used to evaluate AVFs without the risk of radiation exposure, intravenous contrast, or reliance on the operator-dependent modality of color Doppler ultrasonography (CDUS). The objective of our study was to assess the utility of TOF-MR in the evaluation of nonmaturing AVFs and to identify the best clinical situations to use this technology.
  
  
  METHODS
  Consecutive patients with abnormal findings on CDUS or physical examination after AVF creation underwent 3-dimensional (3D) TOF-MR. Imaging was performed at 3 T with a scan acquisition time of approximately 15 min. The technique was similar to head and neck magnetic resonance angiography (MRA), except presaturation bands were not used, thereby allowing simultaneous visualization of both arterial and venous flow. A total of 19 TOF-MR studies were performed.
  
  
  RESULTS
  Nineteen patients underwent imaging and were the focus of this study. Seventeen of 19 TOF-MR studies were of diagnostic quality and yielded findings which enabled the vascular surgeon to take corrective measures. Findings included inflow stenosis, anastomotic narrowing, venous outflow stenosis, and hemodynamically significant venous tributaries. Twelve of 17 patients required conventional digital subtraction angiography (DSA). The congruence rate between TOF-MR and DSA was 83.3%. Four patients (21%) avoided DSA and went directly to definitive surgical treatment including branch ligation (3) or new access (1).
  
  
  CONCLUSIONS
  This is the first report in the literature of successful implementation of 3D TOF-MR to assist in identifying AVF maturation problems. This unique noninvasive imaging modality provides actionable images without contrast or radiation exposure and can obviate the need for invasive diagnostic procedures or provide an anatomic map for planning corrective intervention.
authors.affiliation: Division of Interventional Radiology, Department of Radiology, Naval Medical Center San Diego, San Diego, CA.
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Gonzalez
authors.affiliation: Division of Vascular Surgery, Department of General Surgery, Naval Medical Center San Diego, San Diego, CA.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Casey
authors.affiliation: Division of Interventional Radiology, Department of Radiology, Naval Medical Center San Diego, San Diego, CA.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Drinkwine
authors.affiliation: Division of Vascular Surgery, Department of General Surgery, Naval Medical Center San Diego, San Diego, CA. Electronic address: Jeffrey.s.weiss.mil@mail.mil.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Weiss
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001166:Arteriovenous Shunt, Surgical; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging / Q000628:therapy; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007676:Kidney Failure, Chronic / Q000000981:diagnostic imaging* / Q000628:therapy; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011237:Predictive Value of Tests; D011859:Radiography; D006435:Renal Dialysis; D012189:Retrospective Studies; D014654:Vascular Patency