Magnetic resonance microscopic imaging based on high-order intermolecular multiple-quantum coherences

Cho, Jee-Hyun; Ahn, Sangdoo; Lee, Chul-Hyun; Hong, Kwan Soo; Chung, Kee‐Choo; Chang, Sukkyu; Cheong, Chaejoon; Warren, Warren S.

doi:10.1016/j.mri.2006.09.005

Cited by 7 publications

(10 citation statements)

References 44 publications

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“…The iDQC_EPI and iDQC_SE images were acquired with a CRAZED-type pulse sequence (90°-τ-gradient-120°-[double-area gradient]-2τ-TE/2-180°-TE/2) with EPI and SE readouts at the end of the sequence, respectively [34]. Four-step phase cycling (for the first RF pulse and the receiver phases) was introduced to suppress unwanted coherences such as single-quantum contaminations.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…Because of the intrinsic sensitivity to changes in magnetization and susceptibility structures, iMQC imaging signals provide a fundamentally different contrast mechanism from conventional MRI contrast [27–31], and are particularly well suited to imaging local anisotropy produced by magnetic nanoparticles [32, 33]. Our previous study showed that intermolecular double quantum coherence (iDQC) imaging produced unique contrast that reflected susceptibility structures of small (∼100 μm) air bubbles formed on the walls of capillary tubes [34]. This susceptibility variation can create resonance frequency differences between distant spins that are coupled by intermolecular dipolar interactions.…”

Section: Introductionmentioning

confidence: 99%

“…This susceptibility variation can create resonance frequency differences between distant spins that are coupled by intermolecular dipolar interactions. The iMQC image intensity around the bubbles is then reduced by additional dephasing effects and phase distortions [25, 34, 35]. …”

Section: Introductionmentioning

confidence: 99%

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Detection of iron-labeled single cells by MR imaging based on intermolecular double quantum coherences at 14 T

Cho

Hong

Cho

et al. 2012

Journal of Magnetic Resonance

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To evaluate the efficiency and feasibility of intermolecular multiple quantum coherence (iMQC) magnetic resonance (MR) imaging for single cell detection, we obtained intermolecular double quantum coherence (iDQC) and conventional gradient echo (GE) images of macrophage cells labeled by contrast agents in gel. The iDQC images obtained with echo-planar readout visualized the labeled cells effectively and with a higher contrast than seen in conventional GE images, especially at low planar resolutions and with thick slices. This implies that iDQC imaging with contrast agents could be a good alternative to conventional MR imaging for detecting labeled single cells or cell tracking under favorable conditions.

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Section: Experimental Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Detection of iron-labeled single cells by MR imaging based on intermolecular double quantum coherences at 14 T

Cho

Hong

Cho

et al. 2012

Journal of Magnetic Resonance

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“…As described elsewhere, during the t 1 period, the multiple quantum coherences that correlate with the multi-spins from different molecules should evolve sensitively with the relaxation processes, susceptibility variations, and translational diffusion. 9,17,18 Additionally, during the t 2 period, diffusion could attenuate the strength of the distant dipolar field (or dipolar demagnetizing field), which is created by the modulated z-magnetization, and can convert the iMQCs into detectable signals, while there is no diffusional effect in the conventional PGSE experiment. Hence, the diffusion effect on the signal attenuation with the dipolar field should be considered for both the evolution and detection periods in the CRAZED-type experiments.…”

Section: -12mentioning

confidence: 99%

“…[1][2][3][4][5][6][7][8][9][10][11][12] This feature allows for a wider range of applications in NMR and MR imaging.…”

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confidence: 99%

Analytical and Numerical Calculations of Diffusion Effects on the Intermolecular Multiple Quantum Coherences in Solution NMR

Chung¹,

Jin²,

Won³

et al. 2013

Bulletin of the Korean Chemical Society

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The intermolecular multiple quantum coherences (iMQCs) that are generated by intermolecular dipolar interactions between distant spins on different molecules, have recently gained considerable attention because their properties are intrinsically different from those of conventional single quantum coherences (SQCs) in solution NMR.1-12 This feature allows for a wider range of applications in NMR and MR imaging. 7-12Signal attenuation behaviors of the iMQCs induced by the translational diffusion of correlated molecules in the presence of pulsed field gradients should be different from those of SQCs. However, the diffusion effect on the iMQC signals resulting from intermolecular interactions is not yet well-understood.13-16 In the prototype CRAZED sequence, which differs from the conventional pulsed gradient spin echo (PGSE) experiment, the molecular diffusion affects the evolution of the iMQCs during both the evolution period t 1 and detection period t 2 . As described elsewhere, during the t 1 period, the multiple quantum coherences that correlate with the multi-spins from different molecules should evolve sensitively with the relaxation processes, susceptibility variations, and translational diffusion.9,17,18 Additionally, during the t 2 period, diffusion could attenuate the strength of the distant dipolar field (or dipolar demagnetizing field), which is created by the modulated z-magnetization, and can convert the iMQCs into detectable signals, while there is no diffusional effect in the conventional PGSE experiment. Hence, the diffusion effect on the signal attenuation with the dipolar field should be considered for both the evolution and detection periods in the CRAZED-type experiments.Previous studies have analytically revealed the diffusion effects on the iMQC signals for the limited condition.13-16 In this paper, we analytically show the evolution behavior of an iMQC signal in a CRAZED-type sequence with molecular diffusion effects, and a comparison with numerical simulations conducted using various diffusion coefficients. To distinguish the diffusion effects during the t 1 and t 2 periods, the position of the first encoding gradient pulse was varied from the beginning to the end of the t 1 period. It should be noted that the other dynamics, except for the distant dipolar field (DDF) and diffusion, were ignored in the analytical and numerical calculations to clearly understand the effects of diffusion on the iMQC evolution.In principle, both the quantum and classical treatments yield the same predictions for the iMQCs signal generated by intermolecular dipolar couplings in solution NMR. The quantum picture retains the individual dipolar couplings for all evolution periods and averages them at the end, while the classical picture averages all dipolar couplings first and then make evolution under that mean field.3,17 For evaluating the diffusion effects, the classical approach would be suitable since the modified Bloch equation can easily incorporate the diffusion effects as well as the distant dipolar field...

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Future Horizons of the Brain Science

Kaila

2012

Molecular Imaging of the Brain

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Magnetic resonance microscopic imaging based on high-order intermolecular multiple-quantum coherences

Cited by 7 publications

References 44 publications

Detection of iron-labeled single cells by MR imaging based on intermolecular double quantum coherences at 14 T

Detection of iron-labeled single cells by MR imaging based on intermolecular double quantum coherences at 14 T

Analytical and Numerical Calculations of Diffusion Effects on the Intermolecular Multiple Quantum Coherences in Solution NMR

Future Horizons of the Brain Science

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