Quantification ofin vivo³¹P NMR brain spectra using LCModel

Abstract

Quantification of 31P NMR spectra is commonly performed using line-fitting techniques with prior knowledge. Currently available time- and frequency- domain analysis software includes AMARES (in jMRUI) and CFIT respectively. Another popular frequency domain approach is LCModel, which has been successfully used to fit both 1H and 13C in vivo NMR spectra. To the best of our knowledge LCModel has not been used to fit 31P spectra. This study demonstrates the feasibility of using LCModel to quantify in vivo 31P MR spectra, provided that adequate prior knowledge and LCModel CONTROL parameters are used. Both single-voxel and MRSI data are presented and similar results are obtained with LCModel and with AMARES. This provides a new method for automated, operator-independent analysis of 31P NMR spectra.

CO2 induced pHi changes in the brain of polar fish: a TauCEST application

“…This is highly beneficial compared with 31 P NMR spectroscopy, which displays low resolution due to low sensitivity and a localization usually dependent on the diameter of the surface coil. In previous studies localized 31 P MR spectra with an excellent spectral resolution and small voxels (27–45 mm 3 ) were obtained in mouse brain . Nevertheless, the time resolution for the acquisition of such spectra is usually around 30 min or longer, and the applicability of localized 31 P NMR spectroscopy in a sea water environment still needs to be demonstrated.…”

“…In previous studies localized 31 P MR spectra with an excellent spectral resolution and small voxels (27-45 mm 3 ) were obtained in mouse brain. 64,65 Nevertheless, the time resolution for the acquisition of such spectra is usually around 30 min or longer, and the applicability of localized 31 P NMR spectroscopy in a sea water environment still needs to be demonstrated.…”

Nutritional Ketosis Increases NAD+/NADH Ratio in Healthy Human Brain: An in Vivo Study by 31P-MRS

“…31 P MR spectra were analyzed by LCModel ( 18 ) using a basis-set composed of simulated 31 P spectra of PCr, α-ATP, β-ATP, γ-ATP, Pi int , Pi ext , PE, PC, GPC, GPE, MP, NADH, NAD + , UPDG (uridine diphosphoglucose) with their respective linewidth ( 19 ). [γ-ATP] was assumed to be 3 mM in the human occipital lobe and used as an internal concentration reference.…”

Evidence for a “metabolically inactive” inorganic phosphate pool in adenosine triphosphate synthase reaction using localized 31P saturation transfer magnetic resonance spectroscopy in the rat brain at 11.7 T

“…This averaged dataset was then analyzed with LCModel 16 using a simulated basis set as described in Deelchand et al 17 Both peaks were visible at the expected Pi resonances, one at 4.9 and the other at 5.3 ppm, and the basis set was built accordingly. The exact chemical shift between each Pi peak and PCr resonance was used to calculate pH in each compartment according to this equation: Limiting shifts are ha ¼ 3.27 (acidic species) a ¼ 5.68 (basic species) and deprotonation constant is pKa ¼ 6.73.…”