title: The mamillothalamic tract is a good landmark for the anterior border of the subthalamic nucleus on axial MR images.
abstract: BACKGROUND
  Identification of the subthalamic nucleus (STN) on MR images is difficult, and the use of external landmarks could be of interest for STN targeting in deep brain stimulation (DBS).
  
  
  OBJECTIVE
  Our aim was to explore the relationship between the anteroposterior coordinates of (1) the center of the mamillothalamic tract and (2) the anterior border of the STN on axial MR images.
  
  
  METHODS
  The brains of 16 healthy volunteers were imaged on a 3T MR system. Four millimeters under the anterior-posterior commissure plane, we noted the y coordinates of (1) the center of the mamillothalamic tract and (2) the anterior border of the STN.
  
  
  RESULTS
  The coordinates were y(STN) = 14.7 ± 1.23 mm and y(Tmth) = 14.3 ± 1.13 mm from the posterior commissure for the STN and the mamillothalamic tract, respectively. The mean difference was 0.4 mm (range 0-1 mm). Pearson's coefficient was 0.97 (p < 0.01).
  
  
  CONCLUSIONS
  We observed a strong correlation between the anteroposterior coordinates of the mamillothalamic tract and the anterior border of the STN (which is located between 0 and 1 mm in front of the mamillothalamic tract). The mamillothalamic tract could be a good anterior landmark for STN targeting. It could also be tested for target determination in DBS for severe obsessive-compulsive disorder.
authors.affiliation: UMR 5227, CNRS, Université Bordeaux-2, CHU de Bordeaux, Bordeaux, France. francois.caire @ chu-limoges.fr
authors.forename: François
authors.initials: F
authors.lastname: Caire
authors.forename: Antoine
authors.initials: A
authors.lastname: Maubon
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Moreau
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Cuny
mesh_terms: D000328:Adult; D000368:Aged; D046690:Deep Brain Stimulation / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008326:Mammillary Bodies / Q000033:anatomy & histology*; D008875:Middle Aged; D009434:Neural Pathways / Q000033:anatomy & histology; D013238:Stereotaxic Techniques / Q000295:instrumentation; D020531:Subthalamic Nucleus / Q000033:anatomy & histology*; D013788:Thalamus / Q000033:anatomy & histology*; D055815:Young Adult