Human Acute Cerebral Ischemia: Detection of Changes in Water Diffusion Anisotropy by Using MR Imaging

PURPOSE: To (a) determine the optimal choice of a scalar metric of anisotropy and (b) determine by means of magnetic resonance imaging if changes in diffusion anisotropy occurred in acute human ischemic stroke.

MATERIALS AND METHODS: The full diffusion tensor over the entire brain was measured. To optimize the choice of a scalar anisotropy metric, the performances of scalar indices in simulated models and in a healthy volunteer were analyzed. The anisotropy, trace apparent diffusion coefficient (ADC), and eigenvalues of the diffusion tensor in lesions and contralateral normal brain were compared in 50 patients with stroke.

RESULTS: Changes in anisotropy in patients were quantified by using fractional anisotropy because it provided the best performance in terms of contrast-to-noise ratio as a function of signal-to-noise ratio in simulations. The anisotropy of ischemic white matter decreased (P = .01). Changes in anisotropy in ischemic gray matter were not significant (P = .63). The trace ADC decreased for ischemic gray matter and white matter (P < .001). The first and second eigenvalues decreased in both ischemic gray and ischemic white matter (P < .001). The third eigenvalue decreased in ischemic gray (P = .001) and white matter (P = .03).

CONCLUSION: Gray matter is mildly anisotropic in normal and early ischemic states. However, early white matter ischemia is associated with not only changes in trace ADC values but also significant changes in the anisotropy, or shape, of the water self-diffusion tensor.


  • 1 Warach S, Chien D, Li W, Ronthal M, Edelman RR. Fast magnetic resonance diffusion-weighted imaging of acute human stroke. Neurology 1992; 42:1717-1723.
  • 2 Warach S, Gaa J, Siewert B, Wielopolski P, Edelman R. Acute human stroke studied by whole brain echo planar diffusion-weighted magnetic resonance imaging. Ann Neurol 1995; 37:231-241.
  • 3 Sorensen AG, Buonanno FS, Gonzalez RG, et al. Hyperacute stroke: evaluation with combined multisection diffusion-weighted and hemodynamically weighted echo-planar MR imaging. Radiology 1996; 199:391-401.
  • 4 Le Bihan D, Breton E, Lallemand D, Grenier P, Cabanis E, Laval-Jeantet M. MR imaging of intravoxel incoherent motions: application to diffusion and perfusion in neurologic disorders. Radiology 1986; 161:401-407.
  • 5 Thomsen C, Henriksen O, Ring P. In vivo measurement of water self-diffusion in the human brain by magnetic resonance imaging. Acta Radiol 1987; 28:353-361.
  • 6 Le Bihan D, Breton E, Lallemand D, Aubin ML, Vignaud J, Laval-Jeantet M. Separation of diffusion and perfusion in intravoxel incoherent motion MR imaging. Radiology 1988; 168:497-505.
  • 7 Hajnal J, Doran M, Hall A, et al. MR imaging of anisotropically restricted diffusion of water in the nervous system: technical, anatomic, and pathologic considerations. J Comput Assist Tomogr 1991; 15:1-18.
  • 8 Tsuruda JS, Chew WM, Moseley ME, Norman D. Diffusion-weighted MR imaging of extraaxial tumors. Magn Reson Med 1991; 19:316-320.
  • 9 Chien D, Kwong KK, Gress DR, Buonanno FS, Buxton RB, Rosen BR. MR diffusion imaging of cerebral infarction in humans. AJNR 1992; 13:1097-1102.
  • 10 Welch K, Windham J, Knight R, et al. A model to predict the histopathology of human stroke using diffusion and T2-weighted magnetic resonance imaging. Stroke 1995; 26:1983-1989.
  • 11 Lutsep HL, Albers GW, De Crespigny A, Kamat GN, Marks MP, Moseley ME. Clinical utility of diffusion-weighted magnetic resonance imaging in the assessment of ischemic stroke. Ann Neurol 1997; 41:574-580.
  • 12 Takeda K, Nomura Y, Sakuma H, Tagami T, Okuda Y, Nakagawa T. MR assessment of normal brain development in neonates and infants: comparative study of T1- and diffusion-weighted images. J Comput Assist Tomogr 1997; 21:1-7.
  • 13 Brunberg JA, Chenevert TL, McKeever PE, et al. In vivo MR determination of water diffusion coefficients and diffusion anisotropy: correlation with structural alteration in gliomas of the cerebral hemispheres. AJNR 1995; 16:361-371.
  • 14 de Crespigny AJ, Marks MP, Enzmann DR, Moseley ME. Navigated diffusion imaging of normal and ischemic human brain. Magn Reson Med 1995; 33:720-728.
  • 15 Baird AE, Benfield A, Schlaug G, et al. Enlargement of human cerebral ischemic lesion volumes measured by diffusion-weighted magnetic resonance imaging. Ann Neurol 1997; 41:581-589.
  • 16 Lovblad KO, Baird AE, Schlaug G, et al. Ischemic lesion volumes in acute stroke by diffusion-weighted magnetic resonance imaging correlate with clinical outcome. Ann Neurol 1997; 42:164-170.
  • 17 Schlaug G, Siewert B, Benfield A, Edelman RR, Warach S. Time course of the apparent diffusion coefficient (ADC) abnormality in human stroke. Neurology 1997; 49:113-119.
  • 18 Ulug AM, Beauchamp N, Bryan RN, van Zijl PCM. Absolute quantitation of diffusion constants in human stroke. Stroke 1997; 28:483-490.
  • 19 Chien D, Buxton RB, Kwong KK, Rosen BR. MR diffusion imaging of the human brain. J Comput Assist Tomogr 1990; 14:514-520.
  • 20 Chenevert TL, Brunberg JA, Pipe JG. Anisotropic diffusion in human white matter: demonstration with MR techniques in vivo. Radiology 1990; 177:401-405.
  • 21 Douek P, Turner R, Pekar J, Patronas N, Le Bihan D. MR color mapping of myelin fiber orientation. J Comput Assist Tomogr 1991; 15:923-929.
  • 22 Sakuma H, Nomura Y, Takeda K, et al. Adult and neonatal human brain: diffusional anisotropy and myelination with diffusion-weighted MR imaging. Radiology 1991; 180:229-233.
  • 23 Coremans J, Luypaert R, Verhelle F, Stadnik T, Osteaux M. A method for myelin fiber orientation mapping using diffusion-weighted MR images. Magn Reson Imaging 1994; 12:443-454.
  • 24 Nomura Y, Sakuma H, Takeda K, Tagami T, Okuda Y, Nakagawa T. Diffusional anisotropy of the human brain assessed with diffusion-weighted MR: relation with normal brain development and aging. AJNR 1994; 15:231-238.
  • 25 Pierpaoli C, Jezzard P, Basser PJ, Barnett A, Di Chiro G. Diffusion tensor MR imaging of the human brain. Radiology 1996; 201:637-648.
  • 26 Pierpaoli C, Penix L, De Graba T, Basser PJ, Di Chiro G. Identification of fiber degeneration and organized gliosis in stroke patients by diffusion tensor MRI (abstr) In: Proceedings of the Fourth Meeting of the International Society for Magnetic Resonance in Medicine. Berkeley, Calif: International Society for Magnetic Resonance in Medicine, 1996; 563.
  • 27 Makris N, Worth AJ, Sorensen AG, et al. Morphometry of in vivo human white matter association pathways with diffusion-weighted magnetic resonance imaging. Ann Neurol 1997; 42:951-962.
  • 28 van Gelderen P, de Vleeschouwer MHM, Des Pres D, Pekar J, van Zijl PCM, Moonen CTW. Water diffusion and acute stroke. Magn Reson Med 1994; 31:154-163.
  • 29 Moonen CT, Pekar J, de Vleeschouwer MH, van Gelderen P, van Zijl PC, Des Pres D. Restricted and anisotropic displacement of water in healthy cat brain and in stroke studied by NMR diffusion imaging. Magn Reson Med 1991; 19:327-332.
  • 30 Kajima T, Azuma K, Itoh K, et al. Diffusion anisotropy of cerebral ischemia. Acta Neurochir Suppl (Wien) 1994; 60:216-219.
  • 31 Pierpaoli C, Basser PJ. Toward a quantitative assessment of diffusion anisotropy. Magn Reson Med 1996; 36:893-906.
  • 32 Einstein A. Investigations on the theory of the Brownian movement New York, NY: Dover Publications, 1956.
  • 33 Tanner JE, Stejskal EO. Restricted self-diffusion of protons in colloidal systems by the pulsed-gradient, spin-echo method. J Chem Phys 1968; 49:1768-1777.
  • 34 Stejskal E, Tanner J. Spin diffusion measurements: spin echoes in the presence of a time-dependent field gradient. J Chem Phys 1965; 42:288-292.
  • 35 McKinstry RC, Weiskoff RM, Belliveau JW, et al. Ultrafast MR imaging of water mobility: animal models of altered cerebral perfusion. JMRI 1992; 2:377-384.
  • 36 Basser PJ, Mattiello J, Le Bihan D. MR diffusion tensor spectroscopy and imaging. Biophys J 1994; 66:259-267.
  • 37 Mattiello J, Basser PJ, Le Bihan D. Analytical expressions for the b matrix in NMR diffusion imaging and spectroscopy. J Magn Reson 1994; 108:131-141.
  • 38 Basser PJ, Mattiello J, Le Bihan D. Estimation of the effective self-diffusion tensor from the NMR spin echo. J Magn Reson 1994; 103:247-254.
  • 39 Mattiello J, Basser PJ, Le Bihan D. The b matrix in diffusion tensor echo-planar imaging. Magn Reson Med 1997; 37:292-300.
  • 40 Basser PJ, Pierpaoli C. Microstructural and physiological features of tissues elucidated by quantitative-diffusion tensor MRI. J Magn Reson 1996; 111:209-219.
  • 41 Henkelman RM. Measurement of signal intensities in the presence of noise in MR images. Med Phys 1985; 12:232-233.
  • 42 Gray H. Anatomy of the human body 37th ed. Edinburgh, UK: Longman, 1989; 875.

Article History

Published in print: Sept 1999