title: Three-dimensional anisotropy contrast periodically rotated overlapping parallel lines with enhanced reconstruction (3DAC PROPELLER) on a 3.0T system: a new modality for routine clinical neuroimaging.
abstract: BACKGROUND
  Clinical magnetic resonance imaging (MRI) has recently entered the "high-field" era, and systems equipped with 3.0-4.0T superconductive magnets are becoming the gold standard for diagnostic imaging. While higher signal-to-noise ratio (S/N) is a definite advantage of higher field systems, higher susceptibility effect remains to be a significant trade-off. To take advantage of a higher field system in performing routine clinical images of higher anatomical resolution, we implemented a vector contrast image technique to 3.0T imaging, three-dimensional anisotropy contrast (3DAC), with a PROPELLER (Periodically Rotated Overlapping Parallel Lines with Enhanced Reconstruction) sequence, a method capable of effectively eliminating undesired artifacts on rapid diffusion imaging sequences.
  
  
  METHODS
  One hundred subjects (20 normal volunteers and 80 volunteers with various central nervous system diseases) participated in the study. Anisotropic diffusion-weighted PROPELLER images were obtained on a General Electric (Waukesha, WI, USA) Signa 3.0T for each axis, with b-value of 1100 sec/mm(2). Subsequently, 3DAC images were constructed using in-house software written on MATLAB (MathWorks, Natick, MA, USA).
  
  
  RESULTS
  The vector contrast allows for providing exquisite anatomical detail illustrated by clear identification of all major tracts through the entire brain. 3DAC images provide better anatomical resolution for brainstem glioma than higher-resolution T2 reversed images. Degenerative processes of disease-specific tracts were clearly identified as illustrated in cases of multiple system atrophy and Joseph-Machado disease.
  
  
  CONCLUSIONS
  Anatomical images of significantly higher resolution than the best current standard, T2 reversed images, were successfully obtained. As a technique readily applicable under routine clinical setting, 3DAC PROPELLER on a 3.0T system will be a powerful addition to diagnostic imaging.
authors.affiliation: Center for Integrated Human Brain Science, Brain Research Institute, University of Niigata, 1 Asahimachi, Niigata 951-8585, Japan. tnakada@bri.niigata-u.ac.jp
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nakada
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Matsuzawa
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Fujii
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Takahashi
authors.forename: Masatoyo
authors.initials: M
authors.lastname: Nishizawa
authors.forename: Ingrid L
authors.initials: IL
authors.lastname: Kwee
mesh_terms: D016880:Anisotropy; D002493:Central Nervous System Diseases / Q000473:pathology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male