Purpose To develop a reliable magnetic resonance elastography (MRE)-based method for measuring regional brain stiffness. Methods First, simulation studies were used to demonstrate how stiffness measurements can be biased by changes in brain morphometry, such as those due to atrophy. Adaptive postprocessing methods were created that significantly reduce the spatial extent of edge artifacts and eliminate atrophy-related bias. Second, a pipeline for regional brain stiffness measurement was developed and evaluated for test-retest reliability in 10 healthy control subjects. Results This technique indicates high test-retest repeatability with a typical coefficient of variation of less than 1% for global brain stiffness and less than 2% for the lobes of the brain and the cerebellum. Furthermore, this study reveals that the brain possesses a characteristic topography of mechanical properties, and also that lobar stiffness measurements tend to correlate with one another within an individual. Conclusion The methods presented in this work are resistant to noise- and edge-related biases that are common in the field of brain MRE, demonstrate high test-retest reliability, and provide independent regional stiffness measurements. This pipeline will allow future investigations to measure changes to the brain’s mechanical properties and how they relate to the characteristic topographies that are typical of many neurologic diseases.
References
[1]
Muthupillai R, Lomas DJ, Rossman PJ, Greenleaf JF, Manduca A et al. (1995) Magnetic resonance elastography by direct visualization of propagating acoustic shear waves. Science 269: 1854-1857. doi:10.1126/science.7569924. PubMed: 7569924.
[2]
Yin M, Talwalkar JA, Glaser KJ, Manduca A, Grimm RC et al. (2007) Assessment of Hepatic Fibrosis with Magnetic Resonance Elastography. Clinical Gastroenterology and Hepatology 5: 1207-1213. doi:10.1016/j.cgh.2007.06.012. PubMed: 17916548.
[3]
Streitberger KJ, Sack I, Krefting D, Pfüller C, Braun J et al. (2012) Brain viscoelasticity alteration in chronic-progressive multiple sclerosis. PLOS ONE 7: e29888. doi:10.1371/journal.pone.0029888. PubMed: 22276134.
[4]
Wuerfel J, Paul F, Beierbach B, Hamhaber U, Klatt D et al. (2010) MR-elastography reveals degradation of tissue integrity in multiple sclerosis. NeuroImage 49: 2520-2525. doi:10.1016/j.neuroimage.2009.06.018. PubMed: 19539039.
[5]
Streitberger KJ, Wiener E, Hoffmann J, Freimann FB, Klatt D et al. (2011) In vivo viscoelastic properties of the brain in normal pressure hydrocephalus. NMR Biomed 24: 385-392. PubMed: 20931563.
[6]
Murphy MC, Huston J 3rd, Jack CR Jr., Glaser KJ, Manduca A et al. (2011) Decreased brain stiffness in Alzheimer's disease determined by magnetic resonance elastography. J Magn Reson Imaging 34: 494-498. doi:10.1002/jmri.22707. PubMed: 21751286.
[7]
Murphy MC, Huston J 3rd, Glaser KJ, Manduca A, Meyer FB et al. (2013) Preoperative assessment of meningioma stiffness using magnetic resonance elastography. J Neurosurg 118: 643-648. PubMed: 23082888.
[8]
Xu L, Lin Y, Han JC, Xi JN, Shen H et al. (2007) Magnetic Resonance Elastography of Brain Tumors: Preliminary Results. Acta Radiologica 48: 327-330. doi:10.1080/02841850701199967. PubMed: 17453505.
[9]
Guo J, Hirsch S, Fehlner A, Papazoglou S, Scheel M et al. (2013) Towards an elastographic atlas of brain anatomy. PLOS ONE 8: e71807. doi:10.1371/journal.pone.0071807. PubMed: 23977148.
[10]
Johnson CL, McGarry MD, Gharibans AA, Weaver JB, Paulsen KD et al. (2013) Local mechanical properties of white matter structures in the human brain. NeuroImage 79: 145-152. doi:10.1016/j.neuroimage.2013.04.089. PubMed: 23644001.
[11]
Murphy MC, Huston J 3rd, Jack CR, Glaser KJ, Jones DT et al. (2013) Regional Brain Stiffness Changes Across the Alzheimer's Disase Spectrum. Proc ISMRM 21. p. 2878.
[12]
Glaser KJ, Ehman RL (2009) MR Elastography Inversions Without Phase Unwrapping. Proc ISMRM 17. p. 4669.
[13]
Romano AJ, Bucaro JA, Ehnan RL, Shirron JJ (2000) Evaluation of a material parameter extraction algorithm using MRI-based displacement measurements. IEEE Trans Ultrason Ferroelectr Freq Control 47: 1575-1581. doi:10.1109/58.883546. PubMed: 18238703.
[14]
Manduca A, Oliphant TE, Dresner MA, Mahowald JL, Kruse SA et al. (2001) Magnetic resonance elastography: Non-invasive mapping of tissue elasticity. Med Image Anal 5: 237-254. doi:10.1016/S1361-8415(00)00039-6. PubMed: 11731304.
[15]
Murphy MC, Huston J 3rd, Glaser KJ, Manduca A, Felmlee JP et al. (2012) Phase Correction for Interslice Discontinuities in Multiclice EPI MR Elastography. Proc ISMRM 20. p. 3426.
[16]
Jack CR, Lowe VJ, Senjem ML, Weigand SD, Kemp BJ et al. (2008) C PiB and structural MRI provide complimentary information in imaging of Alzheimer's disease and amnestic mild cognitive impairment 11. Brain 131: 665-680 doi:10.1093/brain/awm336. PubMed: 18263627.
Papazoglou S, Hamhaber U, Braun J, Sack I (2008) Algebraic Helmholtz inversion in planar magnetic resonance elastography. Phys Med Biol 53: 3147-3158. doi:10.1088/0031-9155/53/12/005. PubMed: 18495979.
[19]
Sack I, Streitberger KJ, Krefting D, Paul F, Braun J (2011) The Influence of Physiological Aging and Atrophy on Brain Viscoelastic Properties in Humans. PLOS ONE 6: e23451. PubMed: 21931599.
[20]
Johnson CL, McGarry MD, Van Houten EE, Weaver JB, Paulsen KD, et al. (2012) Magnetic resonance elastography of the brain using multishot spiral readouts with self-navigated motion correction. Magn Reson Med. 2012/09/25 ed.
[21]
Zhang J, Green MA, Sinkus R, Bilston LE (2011) Viscoelastic properties of human cerebellum using magnetic resonance elastography. J Biomech 44: 1909-1913. doi:10.1016/j.jbiomech.2011.04.034. PubMed: 21565346.
[22]
Romano A, Scheel M, Hirsch S, Braun J, Sack I (2012) In vivo waveguide elastography of white matter tracts in the human brain. Magn Reson Med 68: 1410-1422. doi:10.1002/mrm.24141. PubMed: 22252792.
