Quantitative neuropathology by high resolution magic angle spinning proton magnetic resonance spectroscopy

Abstract

We describe a method that directly relates tissue neuropathological analysis to medical imaging. Presently, only indirect and often tenuous relationships are made between imaging (such as MRI or x-ray computed tomography) and neuropathology. We present a biochemistry-based, quantitative neuropathological method that can help to precisely quantify information provided by in vivo proton magnetic resonance spectroscopy (

High‐resolution 1H NMR spectroscopy in organs and tissues using slow magic angle spinning

“…The spectral resolution is poor and worse than the static spectrum shown in Ref. 11 or obtained in an in vivo experiment (5). This is due to the presence of extra macroscopic susceptibility gradients in our sample, resulting from the cylindrical shape of the sample compartment and/or air pockets, generated during the rotor filling.…”

“…11, the lower proton frequency employed in the present study, and the increased T 2 weighting (600 ms) used in Ref. 11. Investigations are in progress to address this issue.…”

“…It is believed that the bulk magnetic susceptibility variations are the main mechanisms responsible for the broadening (9,10). Using cell extracts can eliminate this broadening, but this procedure is time-consuming and may introduce spectral artifacts (9,11). It is well known that the susceptibility broadening can be eliminated by magic angle spinning (MAS), where the sample is rotated about an axis with an angle of 54°44Ј with respect to the external field (12).…”

“…It is well known that the susceptibility broadening can be eliminated by magic angle spinning (MAS), where the sample is rotated about an axis with an angle of 54°44Ј with respect to the external field (12). Indeed, it has been found in a variety of cell systems and tissues that this method improves spectral resolution dramatically (9,11,13, and references therein). A problem with MAS is that when the value of the spinning rate is small compared to the width of the broadening, the resonant peak splits into a group of spinning sidebands (SSBs) separated by the spinning rate.…”

Combined magnetic resonance imaging and spectroscopic imaging approach to molecular imaging of prostate cancer

“…Two major drawbacks of tissue extraction are that 1) the tissue is completely destroyed, preventing any subsequent histopathologic analysis; and 2) labile metabolites can be lost during the extraction process. Solid-state "magic angle spinning" (MAS) NMR techniques have existed for decades; however, they have only recently been applied to intact tissues (94,95). By spinning the sample at a fast rate (Ն2 kHz) and a specific angle ( ϭ 54.7°), MAS dramatically reduces chemical shift anisotropy and dipole-dipole interactions such that solution-like spectra with narrow linewidths can be obtained.…”