title: Feasibility of 1.6-mm isotropic voxel diffusion tensor tractography in depicting limbic fibers.
abstract: BACKGROUND
  We attempted to assess the feasibility of a 1.6-mm isotropic voxel diffusion tensor imaging (DTI) tractography at 3T in visualizing nerve bundles in the limbic system.
  
  
  METHODS
  We examined 20 healthy volunteers by conventional DTI with a voxel size of 1.6 x 1.6 x 3.0 mm and by high-resolution DTI with a voxel size of 1.6 x 1.6 x 1.6 mm and generated tractographs of three limbic nerve bundles: the fornix, cingulum, and uncinate fasciculus. We visually assessed whether these bundles reached their targets and compared their diffusion parameters between the two techniques.
  
  
  RESULTS
  The entire pathways of the fornix, cingulum, and uncinate fasciculus were more readily visualized by high-resolution DTI than by conventional DTI. Among these, the fimbria of the fornix and the uncinate fasciculus adjacent to the temporal pole were identified more frequently by high-resolution DTI (visualization rate 83 and 100%, respectively) than by conventional DTI (visualization rate 63 and 83%, respectively) at a statistical significance of P < 0.05 and P < 0.01, respectively). Fractional anisotropy values in the fornix, cingulum, and uncinate fasciculus by high-resolution DTI were significantly higher than those by conventional DTI (P < 0.01); in contrast, the apparent diffusion coefficient values of all these fibers except that of the fornix remained unchanged between the two techniques.
  
  
  CONCLUSIONS
  The 1.6-mm istropic voxel DTI at 3T is a feasible visualization tool and can improve the precision of tracking nerve bundles of the limbic system.
authors.affiliation: Advanced Medical Research Center, Iwate Medical University, Takizawa, Japan. shunfuji@iwate-med.ac.jp
authors.forename: Shunrou
authors.initials: S
authors.lastname: Fujiwara
authors.forename: Makoto
authors.initials: M
authors.lastname: Sasaki
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kanbara
authors.forename: Takashi
authors.initials: T
authors.lastname: Inoue
authors.forename: Ryonoshin
authors.initials: R
authors.lastname: Hirooka
authors.forename: Akira
authors.initials: A
authors.lastname: Ogawa
mesh_terms: D005240:Feasibility Studies; D006801:Humans; D008032:Limbic System / Q000033:anatomy & histology*