Values Clarification

Quantum dipole interactions and transient hydrogen bond orientation order in cells, cellular membranes and myelin sheath: Implications for MRI signal relaxation, anisotropy, and T1 magnetic field dependence

“…Moreover, in experimental reports, 36–49 the relaxation rate parameters for axons oriented parallel to $$$ {\mathbf{B}}_0 $$$ are always smaller than for the axons perpendicular to $$$ {\mathbf{B}}_0 $$$. Comparing these result to the THB‐predicted angular dependences in Figure 4, we can conclude that the sources of the relaxation anisotropy are the transient hydrogen bonds residing in the bilayers wrapped around axons with the dipole connections mostly parallel to the bilayers normal ($$$ \beta \approx 0 $$$, the cigars‐like distribution with the cigars' main axes perpendicular to the main axonal axis).…”

“…An important property of MR signal in biological tissue is its anisotropy 25 . While initial studies reported anisotropy of MR signal relaxation properties of tendon, 26 skeletal muscle, 27 and trabecular bone 28,29 (see latest discussion in 30 ), later publications reported on the anisotropy of MR signal phase related to myelinated axons microstructural anisotropy 31 and magnetic susceptibility anisotropy, 32–34 as well as anisotropy of MR signal relaxation in brain WM 35–49 …”