Fixed lock-time relaxation dispersion in the rotating frame

Perlo, Juan; Anoardo, Esteban

doi:10.1016/j.jmr.2006.05.013

Cited by 6 publications

(10 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Fig. 2 shows the nutation frequency dispersion of the NMR signal magnitude acquired by using the fixed locktime experiment [3]. Both doped water and liposome suspension curves were measured.…”

Section: Experimental and Resultsmentioning

confidence: 99%

“…The local field caused by secular spin interactions is here defined as the sample average of the residual (time averaged over molecular dynamics) value of the flux density in the position of a given nuclear spin, due to all the contributions of other spins within the molecule, averaged over all possible spinpositions within the molecule. In samples having a weak or null nutation frequency (ν 1 =γB 1 ) T 1ρ (spin-lattice relaxation time in the rotating frame) dispersion, the magnetization amplitude dispersion at fixed lock-time is sensitive to the local field projection along the laboratory-frame quantization axis [3].…”

Section: Introductionmentioning

confidence: 99%

“…It will turn out that the experiment is indecisive about the origin of the nutation frequency dispersion. However, it is already clear for soft matter and mesomorphic systems that usually at weak locking fields, a magnetization destruction occurs in the presence of local fields, provided that the orientations of these fields are non uniform across the sample volume [3,4].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Molecular order sensitive MRI

Farrher

Triviño

Anoardo

2014

2014 IEEE Biennial Congress of Argentina (ARGENCON)

View full text Add to dashboard Cite

We discuss a contrast method for nuclear magnetic resonance imaging (MRI) based on the nutation frequency dispersion of the NMR signal amplitude in the rotating frame. As a practical matter, we test the concept using a specially designed phantom with independent compartments containing doped water (with copper sulfate) and a liposome suspension prepared with dimyristoylphosphatidylcholine. This last was chosen due to the strong nutation frequency dispersion the sample shows as a consequence of the particular molecular order and dynamics of the lipids within the unilamellar membrane, a key factor for the proposed experiment. The used sequence for 1D imaging is a combination of a previously reported fixed lock-time relaxation experiment in the rotating frame and a simple gradient spin-eco. Gross differences exist between T 1ρ -weighted images in the rotating frame and the approach here presented.Resumen-Se discute un método de contraste para imágenes por resonancia magnética (IRM) basada en la dispersión de la frecuencia de nutación en el sistema rotante de la señal magnética nuclear. El concepto se somete a prueba utilizando un fantoma especialmente diseñado con compartimentos independientes, uno de ellos conteniendo agua dopada (con sulfato de cobre) y el otro una suspensión de liposomas en agua deuterada, preparada con DMPC. Esta última elección se debe a la importante dispersión que muestra la frecuencia de nutación en este sistema debido a las propiedades de orden y dinámica molecular de los lípidos en las membranas, un factor clave para el experimento propuesto. La secuencia 1D utilizada para construir la imagen consiste en una combinación de un experimento de relajación a tiempo de lock fijo y un simple eco de espín obtenido aplicando un gradiente.

show abstract

Section: Experimental and Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Molecular order sensitive MRI

Farrher

Triviño

Anoardo

2014

2014 IEEE Biennial Congress of Argentina (ARGENCON)

View full text Add to dashboard Cite

show abstract

“…A revision of these experiments is currently in progress. Scanning the spin-lattice relaxation at the ultra low frequency (ULF) limit demands of two new insights: an improved lowfrequency magnetic field compensation [39,40], and the study of local fields by other experimental set-up avoiding the cycle of the magnetic field [41]. Summarizing, from experimental facts we may observe:…”

Section: Proton Ffc Relaxometry In Liquid Crystalsmentioning

confidence: 99%

Application of field-cycling NMR relaxometry to the study of ultrasound-induced effects in the molecular dynamics and order of mesomorphic materials

Anoardo

2010

Comptes Rendus. Physique

Self Cite

View full text Add to dashboard Cite

“…An understanding of the nature of such local fields was found to be essential to the interpretation of the dispersion profile. Perlo and Anoardo 26 made an attempt to determine the extent to which specific information can be obtained from a rotating frame experiment. The technique consists in the study of the NMR signal dispersion at a fixed spin-lock time, as a function of the radio frequency field intensity.…”

Section: Experimental Aspectsmentioning

confidence: 99%