Signal strength in subsecond FLASH magnetic resonance imaging: The dynamic approach to steady state

1990 ◽  
Vol 17 (6) ◽  
pp. 1004-1010 ◽  
Author(s):  
W. Hänicke ◽  
K. D. Merboldt ◽  
D. Chien ◽  
M. L. Gyngell ◽  
H. Bruhn ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Steady State ◽  
Magnetic Resonance ◽  
Signal Strength ◽  
Resonance Imaging ◽  
Dynamic Approach ◽  
Approach To Steady State

Ocular biometry through fully refocused steady-state magnetic resonance imaging sequence: reliability and agreement with the IOLMaster® 500

2021 ◽  
Author(s):  
Lorenzo Ismael Perez-Sanchez ◽  
Julia Gutierrez-Vazquez ◽  
Maria Satrustegui-Lapetra ◽  
Francisco Ferreira-Manuel ◽  
Juan Jose Arevalo-Manso ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Steady State ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Sequence ◽  
Ocular Biometry ◽  
Imaging Sequence

scholarly journals Characterizing water fingering phenomena in soils using magnetic resonance imaging and multifractal theory

2009 ◽  
Vol 16 (1) ◽  
pp. 159-168 ◽  
Author(s):  
A. Posadas ◽  
R. Quiroz ◽  
A. Tannús ◽  
S. Crestana ◽  
C. M. Vaz
Keyword(s):  
Magnetic Resonance Imaging ◽  
Steady State ◽  
Magnetic Resonance ◽  
Preferential Flow ◽  
Water Movement ◽  
Three Dimensions ◽  
Water Infiltration ◽  
Resonance Imaging ◽  
Flow Process ◽  
Multifractal Theory

Abstract. The study of water movement in soils is of fundamental importance in hydrologic science. It is generally accepted that in most soils, water and solutes flow through unsaturated zones via preferential paths or fingers. This paper combines magnetic resonance imaging (MRI) with both fractal and multifractal theory to characterize preferential flow in three dimensions. A cubic double-layer column filled with fine and coarse textured sand was placed into a 500 gauss MRI system. Water infiltration through the column (0.15×0.15×0.15 m3) was recorded in steady state conditions. Twelve sections with a voxel volume of 0.1×0.1×10 mm3 each were obtained and characterized using fractal and multifractal theory. The MRI system provided a detailed description of the preferential flow under steady state conditions and was also useful in understanding the dynamics of the formation of the fingers. The f(α) multifractal spectrum was very sensitive to the variation encountered at each horizontally-oriented slice of the column and provided a suitable characterization of the dynamics of the process identifying four spatial domains. In conclusion, MRI and fractal and multifractal analysis were able to characterize and describe the preferential flow process in soils. Used together, the two methods provide a good alternative to study flow transport phenomena in soils and in porous media.

Sign in / Sign up

Export Citation Format

Share Document