Magnetic-resonance pore imaging of nonsymmetric microscopic pore shapes.
Imaging of the microstructure of porous media such as biological tissue or porous solids is of high interest in health science and technology, engineering and material science. Magnetic resonance pore imaging (MRPI) is a recent technique based on nuclear magnetic resonance (NMR) which allows us to acquire images of the average pore shape in a given sample. Here we provide details on the experimental design, challenges, and requirements of MRPI, including its calibration procedures. Utilizing a laser-machined phantom sample, we present images of microscopic pores with a hemiequilateral triangular shape even in the presence of NMR relaxation effects at the pore walls. We therefore show that MRPI is applicable to porous samples without a priori knowledge about their pore shape and symmetry. Furthermore, we introduce "MRPI mapping," which combines MRPI with conventional magnetic resonance imaging (MRI). This enables one to resolve microscopic pore sizes and shapes spatially, thus expanding the application of MRPI to samples with heterogeneous distributions of pores.
MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6140, New Zealand.
Stefan Andreas
SA
Hertel
The Photon Factory and the School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand.
Xindi
X
Wang
The Photon Factory and the School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand.
Peter
P
Hosking
The Photon Factory, Department of Physics and School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand.
M Cather
MC
Simpson
MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6140, New Zealand.|Magritek Limited, 32 Salamanca Road, Wellington 6012, New Zealand.
Mark
M
Hunter
MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6140, New Zealand.
Petrik
P
Galvosas
D002138:Calibration; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008962:Models, Theoretical; D016062:Porosity