Dynamic imaging of hyperpolarized 3He distribution in rat lungs using interleaved‐spiral scans

Viallon, Magalie; Berthezène, Yves; Callot, Virginie; Bourgeois, Marc; Humblot, H.; Briguet, A.; Crémillieux, Yannick

doi:10.1002/1099-1492(200006)13:4<207::aid-nbm641>3.3.co;2-7

Cited by 21 publications

(25 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Of particular interest has been the use of hyperpolarized helium (HP 3-He) MRI. Methods include the following: measures of peripheral airspace size (72)(73)(74)(75), visualization of ventilation distribution at high spatial resolution (76)(77)(78)(79), and assessment of gas flow patterns within the lobar and segmental airways (80)(81)(82). Furthermore, the speed of depolarization of HP 3-He enables direct measurement of regional partial pressure of oxygen and thus allows for an inference of regional gas exchange (83)(84)(85).…”

Section: Mrimentioning

confidence: 99%

State of the Art. A Structural and Functional Assessment of the Lung via Multidetector-Row Computed Tomography: Phenotyping Chronic Obstructive Pulmonary Disease

Hoffman

Simon²,

McLennan³

2006

Proceedings of the American Thoracic Society

147

137

View full text Add to dashboard Cite

With advances in multidetector-row computed tomography (MDCT), it is now possible to image the lung in 10 s or less and accurately extract the lungs, lobes, and airway tree to the fifth-through seventh-generation bronchi and to regionally characterize lung density, texture, ventilation, and perfusion. These methods are now being used to phenotype the lung in health and disease and to gain insights into the etiology of pathologic processes. This article outlines the application of these methodologies with specific emphasis on chronic obstructive pulmonary disease. We demonstrate the use of our methods for assessing regional ventilation and perfusion and demonstrate early data that show, in a sheep model, a regionally intact hypoxic pulmonary vasoconstrictor (HPV) response with an apparent inhibition of HPV regionally in the presence of inflammation. We present the hypothesis that, in subjects with pulmonary emphysema, one major contributing factor leading to parenchymal destruction is the lack of a regional blunting of HPV when the regional hypoxia is related to regional inflammatory events (bronchiolitis or alveolar flooding). If maintaining adequate blood flow to inflamed lung regions is critical to the nondestructive resolution of inflammatory events, the pathologic condition whereby HPV is sustained in regions of inflammation would likely have its greatest effect in the lung apices where blood flow is already reduced in the upright body posture.

show abstract

Section: Mrimentioning

confidence: 99%

State of the Art. A Structural and Functional Assessment of the Lung via Multidetector-Row Computed Tomography: Phenotyping Chronic Obstructive Pulmonary Disease

Hoffman

Simon²,

McLennan³

2006

Proceedings of the American Thoracic Society

147

137

View full text Add to dashboard Cite

show abstract

“…Qualitative evaluations of static breath-hold images of 3 He have been shown to be of value in determining the spatial extent of obstruction in CF in adults (7) and more recently in children (8). Dynamic imaging of HP 3 He can provide striking animation of lung ventilation in hu-mans (9 -12) and in animal models (13)(14)(15). The dynamic images are influenced by several physical factors related to the lung environment, the breathing maneuver used, and the pulse sequence design (see Theory section).…”

mentioning

confidence: 99%

Quantitative analysis of regional airways obstruction using dynamic hyperpolarized ³He MRI—Preliminary results in children with cystic fibrosis

Koumellis

Beek

Woodhouse

et al. 2005

Magnetic Resonance Imaging

View full text Add to dashboard Cite

Purpose: To investigate regional airways obstruction in patients with cystic fibrosis (CF) with quantitative analysis of dynamic hyperpolarized (HP) 3 He MRI. Materials and Methods:Dynamic radial projection MRI of HP 3 He gas was used to study respiratory dynamics in a group of eight children with CF. Signal kinetics in a total of seven regions of interest (ROIs; three in each lung, and one in the trachea) were compared with the results of spirometric pulmonary function tests (PFTs). The tracheal signal intensity was used as a form of "input function" to normalize for input flow effects.Results: A pattern of low flow rate in the upper lobes was observed. When the flow measurements from the peripheral ROIs were averaged to obtain an index of flow in the peripheral lung, a good correlation was found (P ϭ 3.74 ϫ 10 -5 ) with the forced expired volume in one second (FEV1). Conclusion:These results suggest that a quantitative measurement of localized airways obstruction in the early stages of CF may be obtained from dynamic 3 He MRI by using the slope of the signal rise as a measure of air flow into the peripheral lung. This study also demonstrates that children can cooperate well with the 3 He MRI technique.

show abstract

“…These sequences tend to be more readily implemented than multishot non-Cartesian methods such as radial projection and spiral imaging (7)(8)(9)(10). By means of computer simulations and a novel method of experimental validation using a variable transverse magnetization, M y (k y ), of the 1 H signal, we reproduced these filters.…”

mentioning

confidence: 99%

k‐Space filtering in 2D gradient‐echo breath‐hold hyperpolarized ³He MRI: Spatial resolution and signal‐to‐noise ratio considerations

Wild

Paley

Viallon

et al. 2002

Magnetic Resonance in Med

Self Cite

View full text Add to dashboard Cite

In this work some of the factors that can influence the signal-tonoise ratio (SNR) and spatial resolution in MR images of inhaled hyperpolarized gases are systematically addressed. In particular, the effects of RF depletion of longitudinal polarization and image gradient diffusion dephasing were assessed in terms of their contribution to a k-space filter. By means of theoretical simulations and a novel method of experimental validation using a variable transverse magnetization of the 1 H signal, systematic quantitative and qualitative investigations of the effects of k-space filtering intrinsic to imaging of hyperpolarized gas were made. A 2D gradient-echo image is considered for a range of flip angles with centric, sequential, and half-Fourier Cartesian phase-encoding strategies, and the results are assessed in terms of SNR and spatial resolution in the reconstructed images. Centric phase encoding was found to give the best SNR at higher flip angles, with a trade-off in spatial resolution compared to sequential phase encoding. A half-Fourier approach potentially offers increased SNR through the use of higher flip angles without compromising the spatial resolution, which is comparable to that achieved with sequential encoding. Magn Reson Med 47:687-695, 2002.

show abstract

Dynamic imaging of hyperpolarized 3He distribution in rat lungs using interleaved‐spiral scans

Cited by 21 publications

References 0 publications

State of the Art. A Structural and Functional Assessment of the Lung via Multidetector-Row Computed Tomography: Phenotyping Chronic Obstructive Pulmonary Disease

State of the Art. A Structural and Functional Assessment of the Lung via Multidetector-Row Computed Tomography: Phenotyping Chronic Obstructive Pulmonary Disease

Quantitative analysis of regional airways obstruction using dynamic hyperpolarized ³He MRI—Preliminary results in children with cystic fibrosis

k‐Space filtering in 2D gradient‐echo breath‐hold hyperpolarized ³He MRI: Spatial resolution and signal‐to‐noise ratio considerations

Contact Info

Product

Resources

About

Dynamic imaging of hyperpolarized 3He distribution in rat lungs using interleaved‐spiral scans

Cited by 21 publications

References 0 publications

State of the Art. A Structural and Functional Assessment of the Lung via Multidetector-Row Computed Tomography: Phenotyping Chronic Obstructive Pulmonary Disease

State of the Art. A Structural and Functional Assessment of the Lung via Multidetector-Row Computed Tomography: Phenotyping Chronic Obstructive Pulmonary Disease

Quantitative analysis of regional airways obstruction using dynamic hyperpolarized 3He MRI—Preliminary results in children with cystic fibrosis

k‐Space filtering in 2D gradient‐echo breath‐hold hyperpolarized 3He MRI: Spatial resolution and signal‐to‐noise ratio considerations

Contact Info

Product

Resources

About

Quantitative analysis of regional airways obstruction using dynamic hyperpolarized ³He MRI—Preliminary results in children with cystic fibrosis

k‐Space filtering in 2D gradient‐echo breath‐hold hyperpolarized ³He MRI: Spatial resolution and signal‐to‐noise ratio considerations