Diffusion‐weighted J‐resolved spectroscopy

Abstract

The proposed technique provided consistent estimates for the ADCs of NAA, Cr, Cho, glutamate + glutamine, and myo-inositol in all subjects and additionally glutathione and scyllo-inositol in all but one subject. Magn Reson Med 78:1235-1245, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Dephasing optimization through coherence order pathway selection (DOTCOPS) for improved crusher schemes in MR spectroscopy

“…The b‐values with a max amplitude of 30 mT/m (most in vivo experiments) were 16, 26, and 467 s/mm 2 , for the Andreychenko, DOTCOPS, and DOTCOPS elongated crushers scheme used in the MEGA‐sLASER experiments, respectively, and with a maximum amplitude of 44 mT/m (phantom experiments) had b‐values of 33, 57, and 1004 s/mm 2 . The approximate 50% reduction in amplitude in creatine observed between rows 3 and 4 in Figure agrees well with the expected reduction of 50% due to diffusion effects calculated using a diffusivity of 0.78 × 10 −3 mm 2 /s for creatine in General Electric's “BRAINO” phantom …”

“…The lipid contamination in The crusher number corresponds to the labels as shown in Figure 1 and Figure 4 agrees well with the expected reduction of 50% due to diffusion effects calculated using a diffusivity of 0.78 × 10 −3 mm 2 /s for creatine in General Electric's "BRAINO" phantom. 30 Similarly, the approximate 10% reduction of amplitude in creatine between rows 3 and 4 in Figure 6 agrees well with the predicted 10% reduction using an in vivo diffusivity of 0.22 × 10 −3 mm 2 /s for creatine. 30 The reduction in amplitude of the residual water peak between rows 3 and 4 in Figure 6 is predicted to be only 30% due to diffusion, however, it is substantially more, indicating that the reduction in amplitude is mostly due to improved crushing efficacy.…”

“…30 Similarly, the approximate 10% reduction of amplitude in creatine between rows 3 and 4 in Figure 6 agrees well with the predicted 10% reduction using an in vivo diffusivity of 0.22 × 10 −3 mm 2 /s for creatine. 30 The reduction in amplitude of the residual water peak between rows 3 and 4 in Figure 6 is predicted to be only 30% due to diffusion, however, it is substantially more, indicating that the reduction in amplitude is mostly due to improved crushing efficacy.…”

In-vivo evaluation of neuronal and glial changes in amyotrophic lateral sclerosis with diffusion tensor spectroscopy

“…Alternatively, if data were acquired at higher field strength fewer NSA would be necessary due to the intrinsically higher SNR. Furthermore, recent technical developments permit assessing the diffusion properties of brain metabolites beyond tNAA, tCr, and tCho ( Landheer et al 2017 ), which may aid the evaluation of pathogenesis in ALS. In particular, myoinositol is of interest as a counterpart to tNAA since it represents the complementary major intracellular compartment in the central nervous system ( Palombo et al 2017 ).…”

Theoretical description of modern1H in Vivo magnetic resonance spectroscopic pulse sequences

“…Furthermore, diffusion‐weighting has been combined with an MQF filter to measure the diffusivity of lactate separate from that of overlapping lipids . A J ‐resolved PRESS sequence has been developed that enables the estimation of diffusivities for 16 different metabolites, and it has been demonstrated that the lactate and lipid signals at 1.3 ppm can also be separated on the basis of their different diffusivities, similar to a 1D application of DOSY. It should also be mentioned that crusher gradients provide some degree of diffusion‐weighting, and although for most non‐diffusion‐weighted sequences the diffusion weighting is negligible, that may not always be the case .…”