ORIGINAL ARTICLE White matter fiber tractography and color mapping of the normal human cerebellum with diffusion tensor imaging Imagerie par tenseur de diffusion et tractographie sélective des voies cérébelleuses du cerveau normal N. Salamon a, * , N. Sicotte b , A. Drain b , A. Frew b , J.R. Alger b , J. Jen b , S. Perlman b , G. Salamon a a Department of Radiology, Section of Neuroradiology, The David Geffen School of Medicine at UCLA Medical Center, 10833 Le Conte avenue, BL-428 CHS 951721, Los Angeles, CA 90095-1721, USA b Department of Neurology, UCLA Medical Center, 10833 Le Conte avenue, BL-428 CHS 951721, Los Angeles, CA 90095-1721, USA This work was supported by NIH grant ROI.EY. 015311.011, by NIH Roadmap, Initiative for Bioinformatics and Computational Biology U54 RR021813 funded by the NCCR, NCBC and NIGMS and by The National Multiple Sclerosis Society JF 2107 KEYWORDS Diffusion tensor imaging (DTI); Tractography; Cerebellar pathways Abstract Diffusion tensor imaging (DTI) color mapping and fiber tractography was used to study the white matter within the cerebellum along with the afferent and efferent tracts associated with the cerebellum in 24 normal human subjects. The most prominent structures that can be readily identified using these DTI techniques are the middle, inferior and superior cerebellar peduncles. Furthermore DTI shows transverse white matter fiber that cross between the two cerebellar hemispheres at the level of the vermis. At the hemispheric level fibers to the dentate, to the emboliform nuclei are clearly visible on DTI as is the afferent pathway represented by the middle cerebellar peduncle. Selective DTI fiber tractography pro- vides very exquisite images of the cerebellar peduncles and of the fibers projecting to and from the cerebellar cortex. This study demonstrates that DTI is complementary to conven- tional MRI in that DTI elucidates the orientation of white matter fiber bundles that are asso- ciated with the cerebellum. Therefore we anticipate that DTI will become an important adjunct to conventional MRI for clinical and basic studies of cerebellar ataxias and congenital disorders involving the cerebellum and brain stem. This work provides a summary of the nor- Journal of Neuroradiology 34 (2007) 115–128 * Corresponding author. E-mail address: nsalamon@mednet.ucla.edu (N. Salamon). 0150-9861/$ - see front matter © 2007 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.neurad.2007.03.002