Theoretical prediction and experimental measurement of the field dependence of the apparent transverse relaxation of hyperpolarized noble gases in lungs

Parra‐Robles, Juan; Viqueira, William Dominguez; Xu, Xiaojun; Ouriadov, Alexei; Santyr, Giles

doi:10.1016/j.jmr.2008.02.009

Cited by 18 publications

(22 citation statements)

References 20 publications

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“…In vivo T 2 Ã values have been predicted to be about 1/3 as large at 3 T compared to 1.5 T for hyperpolarized gases (38). With this assumption, the maximum error in the calculation would be less than 3.6% for the field strength (3 T) used in this study.…”

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confidence: 71%

Comparison of hyperpolarized³He MRI rat lung volume measurement with micro-computed tomography

et al. 2010

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In this study, the upper-limit volume (gas plus partial tissue volume) as well as absolute volume (gas only) of lungs measured with hyperpolarized (3)He-MR imaging is compared with that determined by micro-computed tomography (CT) under similar ventilation conditions in normal rats. Five Brown Norway rats (210-259 g) were ventilated with O(2), alternately with (3)He, using a computer-controlled ventilator, and 3D density-weighted images of the lungs were acquired during a breath hold after six wash-in breaths of (3)He. The rats were then transferred to a micro-CT scanner, and a similar experimental setup was used to obtain images of the lungs during a breath hold of air with an airway pressure equal to that of the MR imaging breath hold. The upper-limit and absolute volumes obtained from (3)He-MR and micro-CT methods were not significantly different (p > 0.05). The good agreement between the lung volumes measured with the two imaging methods suggests that (3)He-MR imaging can be used for quantitative analysis of lung volume changes in longitudinal studies without the exposure to the ionizing radiation which accompanies micro-CT imaging.

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confidence: 71%

Comparison of hyperpolarized³He MRI rat lung volume measurement with micro-computed tomography

et al. 2010

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“…Computer simulations were performed by numerically solving the Bloch-Torrey equations [19,28] using a finite element method for computer models of phantoms A and B and the diffusion sensitizing gradient waveform of Fig. 2.…”

Section: Computer Simulationsmentioning

confidence: 99%

Experimental investigation and numerical simulation of 3He gas diffusion in simple geometries: Implications for analytical models of 3He MR lung morphometry

Parra‐Robles

Ajraoui

Deppe

et al. 2010

Journal of Magnetic Resonance

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“…Moreover, in high magnetic field B 0 , the local effect of susceptibility-induced field inhomogeneities in porous media may interfere with that of the applied gradients and anyhow limits the lifetime T * 2 of transverse local magnetisations to values scaling as 1/B 0 [10,11,12].…”

Section: Theoretical Considerationsmentioning

confidence: 99%

“…Slow acquisition imaging of HP gases in lungs is expected to be most efficient at low or moderate applied fields (e.g., 1-100 mT), since high fields (e.g., 1.5 T and above) induce short values for T * 2 (of the order of 10 ms at 3 T) due to susceptibility-induced field gradients at alveolar scales [10,11,12].…”

Section: Introductionmentioning

confidence: 99%

Achieving high spatial resolution and high SNR in low-field MRI of hyperpolarised gases with Slow Low Angle SHot

Safiullin¹,

Talbot²,

Nacher³

2013

Journal of Magnetic Resonance

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MRI of hyperpolarised gases is usually performed with fast data acquisition to achieve high spatial resolutions despite rapid diffusion-induced signal attenuation. We describe a double-cross k-space sampling scheme suitable for slow low angle shot (SLASH) acquisition and yielding an increased SNR. It consists of a series of anisotropic partial acquisitions with a reduced resolution in the read direction, which alleviates signal attenuation and still provides a high isotropic resolution. The advantages of SLASH imaging over conventional FLASH imaging are evaluated analytically, using numerical lattice calculations, and experimentally in phantom cells filled with hyperpolarised 3 He-N2 gas mixtures. Low-field MRI is performed (here 2.7 mT), a necessary condition to obtain long T * 2 values in lungs for slow acquisition. Two additional benefits of the SLASH scheme over FLASH imaging have been demonstrated: it is less sensitive to the artefacts due to concomitant gradients and it allows measuring apparent diffusion coefficients for an extended range of times.

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Theoretical prediction and experimental measurement of the field dependence of the apparent transverse relaxation of hyperpolarized noble gases in lungs

Cited by 18 publications

References 20 publications

Comparison of hyperpolarized³He MRI rat lung volume measurement with micro-computed tomography

Comparison of hyperpolarized³He MRI rat lung volume measurement with micro-computed tomography

Experimental investigation and numerical simulation of 3He gas diffusion in simple geometries: Implications for analytical models of 3He MR lung morphometry

Achieving high spatial resolution and high SNR in low-field MRI of hyperpolarised gases with Slow Low Angle SHot

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Theoretical prediction and experimental measurement of the field dependence of the apparent transverse relaxation of hyperpolarized noble gases in lungs

Cited by 18 publications

References 20 publications

Comparison of hyperpolarized3He MRI rat lung volume measurement with micro-computed tomography

Comparison of hyperpolarized3He MRI rat lung volume measurement with micro-computed tomography

Experimental investigation and numerical simulation of 3He gas diffusion in simple geometries: Implications for analytical models of 3He MR lung morphometry

Achieving high spatial resolution and high SNR in low-field MRI of hyperpolarised gases with Slow Low Angle SHot

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Comparison of hyperpolarized³He MRI rat lung volume measurement with micro-computed tomography

Comparison of hyperpolarized³He MRI rat lung volume measurement with micro-computed tomography