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Application of the Steady-State Variable Nutation Angle Method for Faster Determinations of Long T 1s-An Approach Useful for the Design of Hyperpolarized MR Molecular Probes.

Jupin M, Gamliel A, Hovav Y, Sosna J, Gomori JM, Katz-Brull R - Magn Reson Insights (2015)

Bottom Line: The T 1 determination of such new molecular probes is crucial for the success of the hyperpolarized observation.Although the inversion-recovery approach remained by and large the standard for T 1 measurements, we show here that the steady-state variable nutation angle approach is faster and may be better suited for the determination of relatively long T 1s in thermal equilibrium.Specifically, the T 1 of a new molecular probe, [uniformly labeled (UL)-13C6, UL-2H8]2-deoxy-d-glucose, is determined here and compared to that of [UL-13C6, UL-2H7]d-glucose.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.

ABSTRACT
In the dissolution-dynamic nuclear polarization technique, molecular probes with long T 1s are preferred. 13C nuclei of small molecules with no directly bonded protons or sp(3 13)C nuclei with proton positions substituted by deuterons may fulfill this requirement. The T 1 determination of such new molecular probes is crucial for the success of the hyperpolarized observation. Although the inversion-recovery approach remained by and large the standard for T 1 measurements, we show here that the steady-state variable nutation angle approach is faster and may be better suited for the determination of relatively long T 1s in thermal equilibrium. Specifically, the T 1 of a new molecular probe, [uniformly labeled (UL)-13C6, UL-2H8]2-deoxy-d-glucose, is determined here and compared to that of [UL-13C6, UL-2H7]d-glucose.

No MeSH data available.


Related in: MedlinePlus

(A) A typical SSVN data set showing the signals of 13C1 of α- and β-[UL-13C6, UL-2H8]2-deoxy-d-glucose at variable nutation angles (θ) acquired with a TR of 14 seconds, 20 repetitions, and five dummy scans. The pulse duration was incremented from one to nine microseconds, with one microsecond steps. One microsecond corresponded to a 8.6° nutation angle. Thus, θ was varied over 8.6–77.4°. (B) A fit of the SSVN data shown in (A) for the β anomer using Equ. 3. The resulting linear fit was Mθ/sin θ = (Mθ/tan θ) 0.377 + 8946 with an R2 of 0.99. According to Equ. 3, the slope (0.377) equals to exp (−TR/T1). Thus, here the T1 value is calculated from the slope for a known TR of 14 seconds to be 14.4 seconds.
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f3-mri-suppl.1-2015-041: (A) A typical SSVN data set showing the signals of 13C1 of α- and β-[UL-13C6, UL-2H8]2-deoxy-d-glucose at variable nutation angles (θ) acquired with a TR of 14 seconds, 20 repetitions, and five dummy scans. The pulse duration was incremented from one to nine microseconds, with one microsecond steps. One microsecond corresponded to a 8.6° nutation angle. Thus, θ was varied over 8.6–77.4°. (B) A fit of the SSVN data shown in (A) for the β anomer using Equ. 3. The resulting linear fit was Mθ/sin θ = (Mθ/tan θ) 0.377 + 8946 with an R2 of 0.99. According to Equ. 3, the slope (0.377) equals to exp (−TR/T1). Thus, here the T1 value is calculated from the slope for a known TR of 14 seconds to be 14.4 seconds.

Mentions: A typical data set for the SSVN method for the C1 position in the [UL-13C6, UL-2H8]2-deoxy-d-glucose sample is shown in Figure 3A. The nutation angle, θ, was varied over ~9–77°, while the TR was fixed at 7 or 14 seconds. These TR values were selected based on our previous work with [UL-13C6, UL-2H7]d-glucose at the same magnetic field22 (see Materials and methods). Nevertheless, we note that the determination of T1 is the aim of the experiment and it is not necessarily known or approximated beforehand. Without a prior estimate of T1, it is likely that at least two measurements at two different TRs can provide increased confidence that the T1 is indeed determined with a suitable TR.


Application of the Steady-State Variable Nutation Angle Method for Faster Determinations of Long T 1s-An Approach Useful for the Design of Hyperpolarized MR Molecular Probes.

Jupin M, Gamliel A, Hovav Y, Sosna J, Gomori JM, Katz-Brull R - Magn Reson Insights (2015)

(A) A typical SSVN data set showing the signals of 13C1 of α- and β-[UL-13C6, UL-2H8]2-deoxy-d-glucose at variable nutation angles (θ) acquired with a TR of 14 seconds, 20 repetitions, and five dummy scans. The pulse duration was incremented from one to nine microseconds, with one microsecond steps. One microsecond corresponded to a 8.6° nutation angle. Thus, θ was varied over 8.6–77.4°. (B) A fit of the SSVN data shown in (A) for the β anomer using Equ. 3. The resulting linear fit was Mθ/sin θ = (Mθ/tan θ) 0.377 + 8946 with an R2 of 0.99. According to Equ. 3, the slope (0.377) equals to exp (−TR/T1). Thus, here the T1 value is calculated from the slope for a known TR of 14 seconds to be 14.4 seconds.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4629631&req=5

f3-mri-suppl.1-2015-041: (A) A typical SSVN data set showing the signals of 13C1 of α- and β-[UL-13C6, UL-2H8]2-deoxy-d-glucose at variable nutation angles (θ) acquired with a TR of 14 seconds, 20 repetitions, and five dummy scans. The pulse duration was incremented from one to nine microseconds, with one microsecond steps. One microsecond corresponded to a 8.6° nutation angle. Thus, θ was varied over 8.6–77.4°. (B) A fit of the SSVN data shown in (A) for the β anomer using Equ. 3. The resulting linear fit was Mθ/sin θ = (Mθ/tan θ) 0.377 + 8946 with an R2 of 0.99. According to Equ. 3, the slope (0.377) equals to exp (−TR/T1). Thus, here the T1 value is calculated from the slope for a known TR of 14 seconds to be 14.4 seconds.
Mentions: A typical data set for the SSVN method for the C1 position in the [UL-13C6, UL-2H8]2-deoxy-d-glucose sample is shown in Figure 3A. The nutation angle, θ, was varied over ~9–77°, while the TR was fixed at 7 or 14 seconds. These TR values were selected based on our previous work with [UL-13C6, UL-2H7]d-glucose at the same magnetic field22 (see Materials and methods). Nevertheless, we note that the determination of T1 is the aim of the experiment and it is not necessarily known or approximated beforehand. Without a prior estimate of T1, it is likely that at least two measurements at two different TRs can provide increased confidence that the T1 is indeed determined with a suitable TR.

Bottom Line: The T 1 determination of such new molecular probes is crucial for the success of the hyperpolarized observation.Although the inversion-recovery approach remained by and large the standard for T 1 measurements, we show here that the steady-state variable nutation angle approach is faster and may be better suited for the determination of relatively long T 1s in thermal equilibrium.Specifically, the T 1 of a new molecular probe, [uniformly labeled (UL)-13C6, UL-2H8]2-deoxy-d-glucose, is determined here and compared to that of [UL-13C6, UL-2H7]d-glucose.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.

ABSTRACT
In the dissolution-dynamic nuclear polarization technique, molecular probes with long T 1s are preferred. 13C nuclei of small molecules with no directly bonded protons or sp(3 13)C nuclei with proton positions substituted by deuterons may fulfill this requirement. The T 1 determination of such new molecular probes is crucial for the success of the hyperpolarized observation. Although the inversion-recovery approach remained by and large the standard for T 1 measurements, we show here that the steady-state variable nutation angle approach is faster and may be better suited for the determination of relatively long T 1s in thermal equilibrium. Specifically, the T 1 of a new molecular probe, [uniformly labeled (UL)-13C6, UL-2H8]2-deoxy-d-glucose, is determined here and compared to that of [UL-13C6, UL-2H7]d-glucose.

No MeSH data available.


Related in: MedlinePlus