| Autor: |
Demberg, Kerstin, Laun, Frederik Bernd, Bertleff, Marco, Bachert, Peter, Kuder, Tristan Anselm |
| Rok vydání: |
2021 |
| Předmět: |
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| Zdroj: |
Phys. Rev. E, 97 (2018) 052412 |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevE.97.052412 |
| Popis: |
This paper presents a novel approach on solving the phase problem in nuclear magnetic resonance (NMR) diffusion pore imaging, a method, which allows imaging the shape of arbitrary closed pores filled with an NMR-detectable medium for investigation of the microstructure of biological tissue and porous materials. Classical q-space imaging composed of two short diffusion-encoding gradient pulses yields, analogously to diffraction experiments, the modulus squared of the Fourier transform of the pore image which entails an inversion problem: An unambiguous reconstruction of the pore image requires both magnitude and phase. Here, the phase information is recovered from the Fourier modulus by applying a phase retrieval algorithm. This allows omitting experimentally challenging phase measurements using specialized temporal gradient profiles. A combination of the hybrid input-output algorithm and the error reduction algorithm was used with dynamically adapting support (shrinkwrap extension). No a priori knowledge on the pore shape was fed to the algorithm except for a finite pore extent. The phase retrieval approach proved successful for simulated data with and without noise and was validated in phantom experiments with well-defined pores using hyperpolarized xenon gas. |
| Databáze: |
arXiv |
| Externí odkaz: |
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