title: A Comparison of Magnetic Resonance Angiography Techniques for the Evaluation of Intracranial Aneurysms Treated With Stent-assisted Coil Embolization.
abstract: OBJECTIVE
  To identify the effective magnetic resonance angiography (MRA) technique to monitor intracranial aneurysms treated with stent-assisted coiling.
  
  
  METHODS
  Retrospective analysis of various MRA techniques was performed in 42 patients. Three neuroradiologists independently compared non-contrast time of flight (ncTOF) MRA of the head, contrast-enhanced time of flight (cTOF) MRA of the head and dynamic contrast-enhanced MRA (CEMRA) of the head and neck or of the head. Digital subtraction angiography (DSA) was available for comparison in 32 cases. Inter-rater agreement (kappa statistic) was assessed.
  
  
  RESULTS
  Artifactual in-stent severe stenosis or flow gap was identified by ncTOF MRA in 23 of 42 cases (55%) and by cTOF MRA in 23 of 38 cases (60%). DSA excluded in-stent stenosis or occlusion in all 32 cases. No difference was noted between ncTOF and cTOF in the demonstration of neck remnants or residual aneurysms in three cases each. CEMRA of the head and neck or of the head was rated superior to ncTOF and cTOF MRA by all three investigators in seven out of eight cases. In one case, all three techniques demonstrated signifcant artifacts due to double stent placement during coiling. The kappa statistic revealed 0.8 agreement between investigators.
  
  
  CONCLUSIONS
  In the assessment of stent-assisted coiling of intracranial aneurysm, both ncTOF and cTOF MRA show similar results. CEMRA tends to show better flow signals in stent and residual aneurysm.
authors.affiliation: Neuroradiology, Penn State Hershey Medical Center.
authors.forename: Krishnamoorthy
authors.initials: K
authors.lastname: Thamburaj
authors.affiliation: Department of Neurosurgery, Penn State Hershey Medical Center.
authors.forename: Kevin
authors.initials: K
authors.lastname: Cockroft
authors.affiliation: Department of Radiology, Penn State Hershey Medical Center.
authors.forename: Amit K
authors.initials: AK
authors.lastname: Agarwal
authors.affiliation: Department of Radiology, Penn State Hershey Medical Center.
authors.forename: Shyam
authors.initials: S
authors.lastname: Sabat
authors.affiliation: Department of Radiology, Penn State Hershey Medical Center.
authors.forename: Paul
authors.initials: P
authors.lastname: Kalapos
keywords: cerebral aneurysm; coil embolization; intracranial stents; magnetic resonance angiography; mra