Physical Principles of Diffusion Imaging

  • Thinesh Sivapatham
  • Elias R. Melhem


Diffusion-weighted imaging (DWI) utilizes the constant random motion of water molecules, called Brownian motion, to depict the movement or diffusion of water in tissue structures. The diffusion of water molecules in the brain provides us with a sensitive window to its underlying physiology and structure. DWI of the brain was introduced into clinical use in the early 1990s, primarily in the detection of acute ischemic stroke. Since that time, advances in technology have resulted in significant improvements in image quality, allowing the application of DWI to the evaluation of a variety of intracranial disease processes, such as infections, neoplasms, demyelinating processes, and trauma. In this chapter, we review the physical principles of DWI, starting with a description of Brownian motion and its relevance to molecular diffusion. We then describe the application of these principles to DWI of the brain using magnetic resonance imaging (MRI). We discuss basic imaging techniques in DWI of the brain, as well as limitations of current techniques, and newer imaging sequences that have been developed. The clinical applications of DWI are discussed in the following chapters.


Apparent Diffusion Coefficient Diffusion Tensor Imaging Magnetic Field Gradient Diffusion Gradient Gradient Pulse 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. 1.
    Moseley ME, Cohen Y, Mintorovitch J, et al. Early detection of regional cerebral ischemia in cats: comparison of diffusion- and T2-weighted MRI and spectroscopy. Magn Reson Med. 1990;14:330–46.PubMedCrossRefGoogle Scholar
  2. 2.
    Chien D, Kwong KK, Gress DR, et al. MR diffusion imaging of cerebral infarction in humans. AJNR Am J Neuroradiol. 1992;13:1097–102.PubMedGoogle Scholar
  3. 3.
    Warach S, Chien D, Li W, et al. Fast magnetic resonance diffusion-weighted imaging of acute human stroke. Neurology. 1992;42:1717–23.PubMedGoogle Scholar
  4. 4.
    van Everdingen KJ, van der Grong J, Kappelle LJ, Ramos LM, Mali WP. Diffusion-weighted magnetic resonance imaging in acute stroke. Stroke. 1998;29(9):1783–90.PubMedCrossRefGoogle Scholar
  5. 5.
    Brown R. A brief account of microscopical observations made in the months of June, July and August 1827 on the particles contained in the pollen of plants, and on the general existence of active molecules in organic and inorganic bodies. Philosophical Magazine. 1828;4:161.Google Scholar
  6. 6.
    Einstein A. In: Furthe R, Cowper AD, editors. Investigations on the Theory of Brownian Motion. New York: Dover; 1956. (Collection of papers translated from German, first published in 1905).Google Scholar
  7. 7.
    Jones DK. Studying connections in the living human brain with diffusion MRI. Cortex. 2008;44(8):936–52.PubMedCrossRefGoogle Scholar
  8. 8.
    Hagmann P, Jonasson L, Maeder P, Thiran JP, Wedeen VJ, Meuli R. Understanding diffusion MR imaging techniques: from scalar ­diffusion-weighted imaging to diffusion tensor imaging and beyond. Radiographics. 2006;26 Suppl 1:S205–23.PubMedCrossRefGoogle Scholar
  9. 9.
    Schaefer PW, Grant PE, Gonzalez RG. Diffusion-weighted MR imaging of the brain. Radiology. 2000;217(2):331–45.PubMedGoogle Scholar
  10. 10.
    Pierpaoli C, Jezzard P, Basser PJ, et al. Diffusion tensor MR imaging of the human brain. Radiology. 1996;201:637–48.PubMedGoogle Scholar
  11. 11.
    Bloch F. Nuclear induction. Phys Rev. 1946;70:460–74.CrossRefGoogle Scholar
  12. 12.
    Bloch F, Hansen WW, Packard M. Nuclear induction. Phys Rev. 1946;69:127.CrossRefGoogle Scholar
  13. 13.
    Purcell EM, Torrey HC, Pound RV. Resonance absorption by nuclear magnetic moments in a solid. Phys Rev. 1946;69:37.CrossRefGoogle Scholar
  14. 14.
    Hahn EL. Spin echoes. Phys Rev. 1950;80:580–94.CrossRefGoogle Scholar
  15. 15.
    Carr HY, Purcell EM. Effects of diffusion on free precession in nuclear magnetic resonance experiments. Phys Rev. 1954;94:630–8.CrossRefGoogle Scholar
  16. 16.
    Torrey HC. Bloch equations with diffusion terms. Phys Rev. 1956;104:563–5.CrossRefGoogle Scholar
  17. 17.
    Stejskal EO, Tanner JE. Spin diffusion measurements: spin echoes in the presence of a time-dependent field gradient. J Chem Phys. 1965;42:288–92.CrossRefGoogle Scholar
  18. 18.
    Mori S, Barker PB. Diffusion magnetic resonance imaging: its principle and applications. Anat Rec. 1999;257(3):102–9.PubMedCrossRefGoogle Scholar
  19. 19.
    Sevick RJ, Kanda F, Mintorovitch J, et al. Cytotoxic brain edema: assessment with diffusion-weighted MR imaging. Radiology. 1992;185(3):687–90.PubMedGoogle Scholar
  20. 20.
    Ebisu T, Naruse S, Horikawa Y, et al. Discrimination between different types of white matter edema with diffusion-weighted MR imaging. J Magn Reson Imaging. 1993;3:863–8.PubMedCrossRefGoogle Scholar
  21. 21.
    Schaefer PW, Buonanno FS, Gonzalez RG, et al. Diffusion-weighted imaging discriminates between cytotoxic and vasogenic edema in a patient with eclampsia. Stroke. 1997;28:1082–5.PubMedCrossRefGoogle Scholar
  22. 22.
    Schwartz R, Mulkern R, Gudbjartsson H, et al. Diffusion-weighted MR imaging in hypertensive encephalopathy: clues to pathogenesis. AJNR Am J Neuroradiol. 1998;19:859–62.PubMedGoogle Scholar
  23. 23.
    Ay H, Buonanno FS, Schaefer PW, et al. Posterior leukoencephalopathy without severe hypertension: utility of diffusion-weighted MRI. Neurology. 1998;51:1369–76.PubMedGoogle Scholar
  24. 24.
    Mukherjee P, McKinstry RC. Reversible posterior leukoencephalopathy syndrome: evaluation with diffusion-tensor MR imaging. Radiology. 2001;219:756–65.PubMedGoogle Scholar
  25. 25.
    Provenzale JM, Petrella JR, Cruz Jr LCH, et al. Quantitative assessment of diffusion abnormalities in posterior reversible encephalo­pathy syndrome. AJNR Am J Neuroradiol. 2001;22:1455–61.PubMedGoogle Scholar
  26. 26.
    Chen PE, Simon JE, Hill MD, et al. Acute ischemic stroke: accuracy of diffusion-weighted MR imaging – effects of b value and cerebrospinal fluid suppression. Radiology. 2006;238(1):232–9.PubMedCrossRefGoogle Scholar
  27. 27.
    Kim HJ, Choi CG, Lee DH, Lee JH, Kim SJ, Suh DC. High-b-value diffusion-weighted MR imaging of hyperacute ischemic stroke at 1.5T. AJNR Am J Neuroradiol. 2005;26(2):208–15.PubMedGoogle Scholar
  28. 28.
    Le Bihan D. Looking into the functional architecture of the brain with diffusion MRI. Nat Rev Neurosci. 2003;4(6):469–80.PubMedCrossRefGoogle Scholar
  29. 29.
    Cleveland GG, Chang DC, Hazlewood CF, Rorschach HE. Nuclear magnetic resonance measurement of skeletal muscle: anisotrophy of the diffusion coefficient of the intracellular water. Biophys J. 1976;16(9):1043–53.PubMedCrossRefGoogle Scholar
  30. 30.
    Moseley ME, Cohen Y, Kucharczyk J, Mintorovitch J, Asgari HS, Wendland MF, et al. Diffusion-weighted MR imaging of anisotropic water diffusion in cat central nervous system. Radiology. 1990;176(2):439–45.PubMedGoogle Scholar
  31. 31.
    Moseley ME, Kucharczyk J, Asgari HS, Norman D. Anisotropy in diffusion-weighted MRI. Magn Reson Med. 1991;19(2):321–6.PubMedCrossRefGoogle Scholar
  32. 32.
    Doran M, Hajnal JV, Van Bruggen N, King MD, Young IR, Bydder GM. Normal and abnormal white matter tracts shown by MR imaging using directional diffusion weighted sequences. J Comput Assist Tomogr. 1990;14(6):865–73.PubMedCrossRefGoogle Scholar
  33. 33.
    Chenevert TL, Brunberg JA, Pipe JG. Anisotropic diffusion in human white matter: demonstration with MR techniques in vivo. Radiology. 1990;177(2):401–5.PubMedGoogle Scholar
  34. 34.
    Thomsen C, Henriksen O, Ring P. In vivo measurement of water self diffusion in the human brain by magnetic resonance imaging. Acta Radiol. 1987;28(3):353–61.PubMedCrossRefGoogle Scholar
  35. 35.
    Hong X, Dixon WT. Measuring diffusion in inhomogeneous systems in imaging mode using antisymmetric sensitizing gradients. J Magn Reson. 1992;99:561–70.Google Scholar
  36. 36.
    Lian J, Williams DS, Lowe IJ. Magnetic resonance imaging in the presence of background gradients and imaging of background ­gradients. J Magn Reson Series A. 1994;106:65–74.CrossRefGoogle Scholar
  37. 37.
    Wimberger DM, Roberts TP, Barkovich AJ, Prayer LM, Moseley ME, Kucharczyk J. Identification of “premyelination” by diffusion-weighted MRI. J Comput Assist Tomogr. 1995;19(1):28–33.PubMedCrossRefGoogle Scholar
  38. 38.
    Prayer D, Roberts T, Barkovich AJ, Prayer L, Kucharczyk J, Moseley M, et al. Diffusion-weighted MRI of myelination in the rat brain following treatment with gonadal hormones. Neuroradiology. 1997;39(5):320–5.PubMedCrossRefGoogle Scholar
  39. 39.
    Beaulieu C, Allen PS. Determinants of anisotropic water diffusion in nerves. Magn Reson Med. 1994;31(4):394–400.PubMedCrossRefGoogle Scholar
  40. 40.
    Beaulieu C, Allen PS. Water diffusion in the giant axon of the squid: implications for diffusion-weighted MRI of the nervous system. Magn Reson Med. 1994;32(5):579–83.PubMedCrossRefGoogle Scholar
  41. 41.
    Beaulieu C, Allen PS. An in vitro evaluation of the effects of local magnetic-susceptibility-induced gradients on anisotropic water ­diffusion in nerve. Magn Reson Med. 1996;36(1):39–44.PubMedCrossRefGoogle Scholar
  42. 42.
    Beaulieu C. The basis of anisotropic water diffusion in the nervous system – a technical review. NMR Biomed. 2002;15(7–8):435–55.PubMedCrossRefGoogle Scholar
  43. 43.
    Burdette JH, Elster AD, Ricci PE. Acute cerebral infarction: quantification of spin-density and T2 shine-through phenomena on ­diffusion-weighted MR images. Radiology. 1999;212(2):333–9.PubMedGoogle Scholar
  44. 44.
    Pierpaoli C, Jezzard P, Basser PJ, Barnett A, Di Chiro G. Diffusion tensor MR imaging of the human brain. Radiology. 1996;201(3):637–48.PubMedGoogle Scholar
  45. 45.
    Hüppi PS, Maier SE, Peled S, Zientara GP, Barnes PD, Jolesz FA, et al. Microstructural development of human newborn cerebral white matter assessed in vivo by diffusion tensor magnetic resonance imaging. Pediatr Res. 1998;44(4):584–90.PubMedCrossRefGoogle Scholar
  46. 46.
    Neil JJ, Shiran SI, McKinstry RC, Schefft GL, Snyder AZ, Almli CR, et al. Normal brain in human newborns: apparent diffusion coefficient and diffusion anisotropy measured by using diffusion tensor MR imaging. Radiology. 1998;209(1):57–66.PubMedGoogle Scholar
  47. 47.
    Mukherjee P, Miller JH, Shimony JS, Conturo TE, Lee BC, Almli CR, et al. Normal brain maturation during childhood: developmental trends characterized with diffusion-tensor MR imaging. Radiology. 2001;221(2):349–58.PubMedCrossRefGoogle Scholar
  48. 48.
    Mukherjee P, McKinstry RC. Diffusion tensor imaging and tracto­graphy of human brain development. Neuroimaging Clin N Am. 2006;16(1):19–43. vii.PubMedCrossRefGoogle Scholar
  49. 49.
    Mukherjee P, Miller JH, Shimony JS, Philip JV, Nehra D, Snyder AZ, et al. Diffusion-tensor MR imaging of gray and white matter development during normal human brain maturation. AJNR Am J Neuroradiol. 2002;23(9):1445–56.PubMedGoogle Scholar
  50. 50.
    McGraw P, Liang L, Provenzale JM. Evaluation of normal age-related changes in anisotropy during infancy and childhood as shown by diffusion tensor imaging. AJR Am J Roentgenol. 2002;179(6):1515–22.PubMedGoogle Scholar
  51. 51.
    Schneider JF, Il’yasov KA, Hennig J, Martin E. Fast quantitative diffusion-tensor imaging of cerebral white matter from the neonatal period to adolescence. Neuroradiology. 2004;46(4):258–66.PubMedCrossRefGoogle Scholar
  52. 52.
    Snook L, Paulson LA, Roy D, Phillips L, Beaulieu C. Diffusion tensor imaging of neurodevelopment in children and young adults. Neuroimage. 2005;26(4):1164–73.PubMedCrossRefGoogle Scholar
  53. 53.
    Hermoye L, Saint-Martin C, Cosnard G, Lee SK, Kim J, Nassogne MC, et al. Pediatric diffusion tensor imaging: normal database and observation of the white matter maturation in early childhood. Neuroimage. 2006;29(2):493–504.PubMedCrossRefGoogle Scholar
  54. 54.
    Gideon P, Thomsen C, Henriksen O. Increased self-diffusion of brain water in normal aging. J Magn Reson Imaging. 1994;4(2):185–8.PubMedCrossRefGoogle Scholar
  55. 55.
    Chun T, Filippi CG, Zimmerman RD, Uluğ AM. Diffusion changes in the aging human brain. AJNR Am J Neuroradiol. 2000;21(6):1078–83.PubMedGoogle Scholar
  56. 56.
    Engelter ST, Provenzale JM, Petrella JR, et al. The effect of aging on the apparent diffusion coefficient of normal appearing white matter. AJR Am J Roentgenol. 2000;175:425–30.PubMedGoogle Scholar
  57. 57.
    Chen ZG, Li TQ, Hindmarsh T. Diffusion tensor trace mapping in normal adult brain using single-shot EPI technique. A methodological study of the aging brain. Acta Radiol. 2001;42(5):447–58.PubMedGoogle Scholar
  58. 58.
    Nusbaum AO, Tang CY, Buchsbaum MS, Wei TC, Atlas SW. Regional and global changes in cerebral diffusion with normal aging. AJNR Am J Neuroradiol. 2001;22(1):136–42.PubMedGoogle Scholar
  59. 59.
    Moseley M. Diffusion tensor imaging and aging – a review. NMR Biomed. 2002;15(7–8):553–60.PubMedCrossRefGoogle Scholar
  60. 60.
    Le Bihan D, Poupon C, Amadon A, Lethimonnier F. Artifacts and pitfalls in diffusion MRI. J Magn Reson Imaging. 2006;24(3):478–88.PubMedCrossRefGoogle Scholar
  61. 61.
    Mukherjee P, Chung SW, Berman JI, Hess CP, Henry RG. Diffusion tensor MR imaging and fiber tractography: technical considerations. AJNR Am J Neuroradiol. 2008;29(5):843–52.PubMedCrossRefGoogle Scholar
  62. 62.
    Bammer R. Basic principles of diffusion-weighted imaging. Eur J Radiol. 2003;45(3):169–84.PubMedCrossRefGoogle Scholar
  63. 63.
    Mukherjee P, Berman JI, Chung SW, Hess CP, Henry RG. Diffusion tensor MR imaging and fiber tractography: theoretic underpinnings. AJNR Am J Neuroradiol. 2008;29(4):632–41. Epub 2008 Mar 13. Review.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  1. 1.Department of RadiologyHospital of the University of PennsylvaniaPhiladelphiaUSA
  2. 2.Department of RadiologyUniversity of PennsylvaniaPhiladelphiaUSA

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