title: Comparative evaluation of the geometrical accuracy of intravascular magnetic resonance imaging: a phantom study.
abstract: OBJECTIVE
  To evaluate and compare the accuracy of cross-sectional imaging using an intravascular antenna in the context of vascular morphological measurements performed during a magnetic resonance imaging (MRI)-guided vascular intervention.
  
  
  METHODS
  Cross-sectional imaging of a multimodality vascular phantom was performed using intravascular and surface MRI, multidetector computed tomography, and intravascular ultrasound (IVUS). Using a balanced steady-state free-precession sequence, 18 sequences parameters sets were investigated (12 for intravascular MRI and 6 for surface MRI). Vessel diameters for all images and modalities were computed using an automated vessel segmentation algorithm.
  
  
  RESULTS
  Using IVUS as a gold standard, imaging using an intravascular antenna leads to an increase in geometrical accuracy in comparison to traditional surface MRI. This level of accuracy appears to follow a significant inverse proportionality relation in respect to vessel wall signal-to-noise ratio (SNR). Taking into account the rapid decrease in SNR as a function of the distance to the intravascular antenna, these results imply that, for a given level of geometrical accuracy, faster sequences can be used for the imaging of smaller vessels.
  
  
  CONCLUSIONS
  Imaging using an intravascular antenna appears as a valuable assistance to increase the accuracy of vascular morphological measurements. This increase in geometrical accuracy would be beneficial during the realization of an MRI-guided intervention, either to perform pretreatment measurements or to assess the outcome of the procedure. Acquisition parameters should be tailored to vessel size and procedural time constraints.
authors.affiliation: Département de Radiologie, Centre Hospitalier de l'Université de Montréal, Hôpital Notre-Dame, 1560 Sherbrooke Est, Montreal, Quebec, Canada.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Gilbert
authors.forename: Gilles
authors.initials: G
authors.lastname: Soulez
authors.forename: Gilles
authors.initials: G
authors.lastname: Beaudoin
mesh_terms: D019412:Anatomy, Cross-Sectional / Q000379:methods*; D001158:Arteries / Q000033:anatomy & histology*; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity