title: Visualization of vascular compression of the trigeminal nerve with high-resolution 3T MRI: a prospective study comparing preoperative imaging analysis to surgical findings in 40 consecutive patients who underwent microvascular decompression for trigeminal neuralgia.
abstract: BACKGROUND
  High-resolution three-dimensional (3D) magnetic resonance imaging (MRI) has demonstrated its ability to predict fine trigeminal neurovascular anatomy.
  
  
  OBJECTIVE
  To address the predictive value of 3-Tesla (3T) MRI in detecting and assessing features of neurovascular compression (NVC), particularly regarding the degree of compression exerted on the root, in patients who underwent microvascular decompression (MVD) for classic primary trigeminal neuralgia.
  
  
  METHODS
  This prospective study includes 40 consecutive patients who underwent MVD for classic primary trigeminal neuralgia. All patients underwent a preoperative 3T MRI with 3D T2-weighted driven equilibrium (DRIVE), 3D time-of-flight (TOF) magnetic resonance angiography (MRA), and 3D T1-weighted gadolinium-enhanced sequences in combination. Evaluations were performed by 2 independent observers and compared with the operative findings.
  
  
  RESULTS
  For prediction of NVC, image analysis corresponded with surgical findings in 39 cases. Of the 3 patients in whom image analysis did not show NVC, 2 did not have NVC at the time of intraoperative observation. MRI sensitivity was 97.4% (37/38), and specificity was 100% (2/2). The kappa coefficients (κ) for predicting the offending vessel, its location, and the site of compression were 0.882, 0.813, and 0.942, respectively. Image analysis correctly defined the severity of the compression in 31 of the 37 cases. The κ coefficients predicting the degree of compression were 0.813, 0.833, and 0.852, respectively, for Grades 1 (simple contact), 2 (distortion), and 3 (marked indentation).
  
  
  CONCLUSIONS
  3T MRI using 3D T2-weighted DRIVE in combination with 3D TOF-MRA and 3D T1-weighted gadolinium-enhanced sequences proved to be reliable in detecting NVC and in predicting the degree of root compression, the outcome being correlated with the latter.
authors.affiliation: Department of Neurosurgery, University Lyon 1, Lyon, France. prlleal@hotmail.com
authors.forename: Paulo Roberto Lacerda
authors.initials: PR
authors.lastname: Leal
authors.forename: Marc
authors.initials: M
authors.lastname: Hermier
authors.forename: Miguel Angelo
authors.initials: MA
authors.lastname: Souza
authors.forename: Gerardo
authors.initials: G
authors.lastname: Cristino-Filho
authors.forename: Jean Claude
authors.initials: JC
authors.lastname: Froment
authors.forename: Marc
authors.initials: M
authors.lastname: Sindou
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005682:Gadolinium; D006801:Humans; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography / Q000379:methods; D008279:Magnetic Resonance Imaging; D008297:Male; D061145:Microvascular Decompression Surgery / Q000379:methods*; D008875:Middle Aged; D057234:Preoperative Period; D011446:Prospective Studies; D016896:Treatment Outcome; D014276:Trigeminal Nerve / Q000473:pathology*; D014277:Trigeminal Neuralgia / Q000473:pathology* / Q000601:surgery*; D055815:Young Adult
chemical_list: D005682:Gadolinium