title: Microstructural information from angular double-pulsed-field-gradient NMR: From model systems to nerves.
abstract: OBJECTIVE
  To evaluate the ability of angular double-pulsed-field gradient (d-PFG) MR to provide microstructural information in complex phantoms and fixed nerves.
  
  
  METHODS
  We modeled the signal in angular d-PFG MR experiments performed on phantoms of increasing complexity where the ground truth is known a priori. After analyzing the microstructural features of such phantoms the same methodology was used to study microstructural features in fixed nerves.
  
  
  RESULTS
  We found that our modeling is able to determine with high accuracy and with very little prior knowledge the sizes and relative fractions of the restricted components as well as the fraction of the free diffusing water molecules. The same approach was used to study nerve microstructure. We found the apparent averaged axonal diameter (AAD) to be 2.3 ± 0.2 μm. However, here the results depended, to some extent, on the parameters used to collect the data and were affected by the diffusion time.
  
  
  CONCLUSIONS
  Modeling of the angular d-PFG MR signal provides a means to obtain accurate microstructural information in complex phantoms where the ground truth is known. This approach also seems to be suitable for obtaining microstructural features in fixed nerves. Magn Reson Med 74:25-32, 2015. © 2014 Wiley Periodicals, Inc.
authors.affiliation: School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Science, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Darya
authors.initials: D
authors.lastname: Morozov
authors.affiliation: School of Mathematical Sciences, The Raymond and Beverly Sackler Faculty of Exact Science, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Leah
authors.initials: L
authors.lastname: Bar
authors.affiliation: School of Mathematical Sciences, The Raymond and Beverly Sackler Faculty of Exact Science, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Nir
authors.initials: N
authors.lastname: Sochen
authors.affiliation: School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Science, Tel Aviv University, Tel Aviv, Israel.|Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Yoram
authors.initials: Y
authors.lastname: Cohen
keywords: NMR spectroscopy; diffusion NMR; double-pulsed-field-gradient (d-PFG); microstructure; nerve