Book chapter
Diffusion MRI acquisition for tractography: Diffusion encoding
Handbook of Diffusion MR Tractography, pp.103-121
Academic Press
2025
DOI: 10.1016/B978-0-12-818894-1.00001-X
Abstract
This is the first of three chapters (this chapter and Chapters 7 and 8) on diffusion MRI acquisition for tractography. For tractography, the acquisition is optimized for the estimation of fiber orientation. This chapter covers the creation of diffusion contrast. This is largely independent of the image encoding part of the MRI sequence, which is covered in Chapter 7. Unless explicitly stated, this chapter is focused on tractography of in vivo adult human brain. Considerations for tractography acquisition outside the in vivo adult human brain are covered in Chapters 8 and 32. This chapter first describes the creation of diffusion contrast by spin dephasing. It introduces the parameters that describe diffusion encoding: q, diffusion time, and b, and describes signal representations for the diffusion encoded signal. Next, MRI hardware, including field strength, gradient coils, shim coils, and RF coils, is discussed in the context of diffusion encoding. Considerations for the choice of diffusion encoding parameters (b-values, diffusion encoding directions) for tractography are then detailed. The chapter then covers artifacts that can be mitigated by changes to the diffusion encoding itself, including artifacts caused by eddy currents, concomitant field gradients, gradient nonlinearity, system drift, incoherent motion, and vibration. Artifacts related to the rest of the sequence and postprocessing artifact reduction are covered later in Chapters 7 and 9. This chapter concludes with a brief introduction to diffusion sequence variations that can be achieved by varying the q-sampling and/or diffusion time, including nonlinear diffusion encoding.
Details
- Title: Subtitle
- Diffusion MRI acquisition for tractography: Diffusion encoding
- Creators
- Jennifer S.W. Campbell - McConnell Brain Imaging CentreSteven H. Baete - New York UniversityJulien Cohen-Adad - Polytechnique MontréalJ. Donald Tournier - King's College LondonFilip Szczepankiewicz - Harvard Medical SchoolChristian Beaulieu - University of AlbertaCorey A. Baron - Western UniversityMerry Mani - University of IowaKawin Setsompop - Stanford UniversityCongyu Liao - Stanford UniversityChristine L. Tardif - McConnell Brain Imaging CentreSjoerd B. Vos - The University of Western AustraliaAnastasia Yendiki - Harvard Medical SchoolIlana R. Leppert - McConnell Brain Imaging CentreEls Fieremans - New York UniversityG. Bruce Pike - University of Calgary
- Resource Type
- Book chapter
- Publication Details
- Handbook of Diffusion MR Tractography, pp.103-121
- DOI
- 10.1016/B978-0-12-818894-1.00001-X
- Publisher
- Academic Press; London, United Kingdom
- Language
- English
- Date published
- 2025
- Academic Unit
- Radiology; Iowa Neuroscience Institute
- Record Identifier
- 9984828224302771
Metrics
3 Record Views