Three-dimensional analysis of shear wave propagation observed by in vivo magnetic resonance elastography of the brain

2007 ◽  
Vol 3 (1) ◽  
pp. 127-137 ◽  
Author(s):  
U. Hamhaber ◽  
I. Sack ◽  
S. Papazoglou ◽  
J. Rump ◽  
D. Klatt ◽  
...  
2007 ◽  
Vol 16 (11) ◽  
pp. 1867-1874 ◽  
Author(s):  
Ryutaro Fujii ◽  
Hironobu Sakaura ◽  
Yoshihiro Mukai ◽  
Noboru Hosono ◽  
Takahiro Ishii ◽  
...  

2004 ◽  
Vol 52 (4) ◽  
pp. 842-850 ◽  
Author(s):  
Ingolf Sack ◽  
Christopher K. Mcgowan ◽  
Abbas Samani ◽  
Chris Luginbuhl ◽  
Wendy Oakden ◽  
...  

2005 ◽  
Vol 38 (11) ◽  
pp. 2198-2203 ◽  
Author(s):  
Qingshan Chen ◽  
Stacie I. Ringleb ◽  
Armando Manduca ◽  
Richard L. Ehman ◽  
Kai-Nan An

2016 ◽  
Vol 2016 ◽  
pp. 1-12
Author(s):  
Z. Hashemiyan ◽  
P. Packo ◽  
W. J. Staszewski ◽  
T. Uhl

Properties of soft biological tissues are increasingly used in medical diagnosis to detect various abnormalities, for example, in liver fibrosis or breast tumors. It is well known that mechanical stiffness of human organs can be obtained from organ responses to shear stress waves through Magnetic Resonance Elastography. The Local Interaction Simulation Approach is proposed for effective modelling of shear wave propagation in soft tissues. The results are validated using experimental data from Magnetic Resonance Elastography. These results show the potential of the method for shear wave propagation modelling in soft tissues. The major advantage of the proposed approach is a significant reduction of computational effort.


2019 ◽  
Vol 40 (5) ◽  
pp. 991-1001 ◽  
Author(s):  
Felix Schrank ◽  
Carsten Warmuth ◽  
Heiko Tzschätzsch ◽  
Bernhard Kreft ◽  
Sebastian Hirsch ◽  
...  

In-vivo brain viscoelasticity measured by magnetic resonance elastography (MRE) is a sensitive imaging marker for long-term biophysical changes in brain tissue due to aging and disease; however, it is still unknown whether MRE can reveal short-term periodic alterations of brain viscoelasticity related to cerebral arterial pulsation (CAP). We developed cardiac-gated steady-state MRE (ssMRE) with spiral readout and stroboscopic sampling of continuously induced mechanical vibrations in the brain at 20, 31.25, and 40 Hz frequencies. Maps of magnitude |G*| and phase ϕ of the complex shear modulus were generated by multifrequency dual visco-elasto inversion with a temporal resolution of 40 ms over 4 s. The method was tested in 12 healthy volunteers. During cerebral systole, |G*| decreased by 6.6 ± 1.9% (56 ± 22 Pa, p < 0.001, mean ± SD), whereas ϕ increased by 0.5 ± 0.5% (0.006 ± 0.005 rad, p = 0.002). The effect size of CAP-induced softening slightly decreased with age by 0.10 ± 0.05% per year ( p = 0.04), indicating lower cerebral vascular compliance in older individuals. Our data show for the first time that the brain softens and becomes more viscous during systole, possibly due to an effect of CAP-induced arterial expansion and increased blood volume on effective-medium tissue properties. This sensitivity to vascular-solid tissue interactions makes ssMRE potentially useful for detection of cerebral vascular disease.


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