Molecular, dynamic, and structural origin of inhomogeneous magnetization transfer in lipid membranes
Year: 2016
Type: article
Abstract: Purpose To elucidate the dynamic, structural, and molecular properties that create inhomogeneous magnetization transfer (ihMT) contrast. Methods Amphiphilic lipids, lamellar phospholipids with cholesterol, and bovine spinal cord (BSC) specimens were examined along with nonlipid systems. Magnetization transfer (MT), enhanced MT (eMT, obtained with double‐sided radiofrequency saturation), ihMT (MT – eMT), and dipolar relaxation, T1D, were measured at 2.0 and 11.7 T. Results The amplitude of ihMT ratio (ihMTR) is positively correlated with T1D values. Both ihMTR and T1D increase with increasing temperature in BSC white matter and in phospholipids and decrease with temperature in other lipids. Changes in ihMTR with temperature arise primarily from alterations in MT rather than eMT. Spectral width of MT, eMT, and ihMT increases with increasing carbon chain length. Conclusions Concerted motions of phospholipids in white matter decrease proton spin diffusion leading to increased proton T1D times and increased ihMT amplitudes, consistent with decoupling of Zeeman and dipolar spin reservoirs. Molecular specificity and dynamic sensitivity of ihMT contrast make it a suitable candidate for probing myelin membrane disorders. Magn Reson Med 77:1318–1328, 2017. © 2016 International Society for Magnetic Resonance in Medicine
Source: Magnetic Resonance in Medicine
DOI: 10.1002/mrm.26210
Institution: University of Michigan
Language: English
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: green
Award: G1815451664
OpenAlex ID: W2322491063