Purpose To assess the sensitivity of hyperpolarized 129 Xe chemical shift saturation recovery (CSSR) technique for noninvasive quantification changes to lung microstructure and function in idiopathic pulmonary fibrosis (IPF) systemic sclerosis (SSc). Methods Ten healthy volunteers, four subjects with SSc IPF were scanned at 1.5 T. A CSSR pulse sequence was implemented using binomial‐composite radiofrequency pulses monitor magnetization tissues blood plasma (T/P) red cells (RBCs). The...

<h3>Background</h3> Collateral ventilation has been proposed as a mechanism of compensation respiratory function in obstructive lung diseases but observations it vivo are limited. The assessment collateral with an imaging technique might help to gain insight into physiology and assist the planning new bronchoscopic techniques for treating emphysema. <h3>Objective</h3> To obtain images delayed that be related over period single breath-hold patients chronic pulmonary disease (COPD)....

Multiple-breath washout hyperpolarized (3)He MRI was used to calculate regional parametric images of fractional ventilation (r) as the ratio fresh gas entering a volume unit total end inspiratory unit. Using single dose inhaled and acquisition time under 1 min, measured by dynamic acquisitions during successive breaths with fixed delay. A two-dimensional (2D) imaging protocol investigated in four healthy subjects supine position, second capability extending three-dimensional (3D) covering...

In this work, the production rate of a spin-exchange optical pumping 129Xe gas polarizer was optimized for routine generation hyperpolarized in vivo lung MRI. This system uses narrow (∼ 0.1 nm linewidth), tuneable external cavity laser (operating at ∼25 W) SEOP 3% mixtures Xe inside mid-pressure (2 bars) cell 491 cm3 volume. Under regime, theoretical and experimentally measured polarizations were calculated to be 24% 12%, respectively, flow 300 sccm temperature 373 K. The photon efficiency...

Abstract Purpose Hyperpolarized 129 Xe MRI benefits from non‐Cartesian acquisitions that sample k‐space efficiently and rapidly. However, their reconstructions are complex burdened by decay processes unique to hyperpolarized gas. Currently used gridded prone artifacts caused magnetization ill‐suited for undersampling. We present a compressed sensing (CS) reconstruction approach incorporates in the forward model, thereby producing images with increased sharpness contrast, even undersampled...

In this work, the application of compressed sensing techniques to acquisition and reconstruction hyperpolarized 3He lung MR images was investigated. The sparsity in wavelet domain investigated through simulations based on fully sampled Cartesian two-dimensional three-dimensional ventilation images, k-spaces 2D 3D were undersampled randomly reconstructed by minimizing L1 norm. simulation results show that temporal resolution can be readily improved a factor 2 for 4 5 imaging with levels...

To re-engineer a standard clinical magnetic resonance (MR) imaging system to enable the acquisition, in same breath hold, of lung images from two hyperpolarized gases (helium 3 [(3)He] and xenon 129 [(129)Xe]) with simultaneous registered anatomic proton (hydrogen 1 [(1)H]) MR structure.Studies (3)He (129)Xe were performed National Research Ethics Committee approval, informed consent volunteer. (1)H-(3)He-(129)Xe was achieved by using mutually decoupled nested radiofrequency coil hardware...

Purpose To demonstrate three‐dimensional (3D) multiple b ‐value diffusion‐weighted (DW) MRI of hyperpolarized 3 He gas for whole lung morphometry with compressed sensing (CS). Methods A fully‐sampled, two ‐value, 3D DW‐MRI dataset was acquired from the lungs a healthy volunteer and retrospectively undersampled in k y z phase‐encoding directions CS simulations. Optimal k‐space undersampling patterns were determined by minimizing mean absolute error between reconstructed fully‐sampled apparent...

In hyperpolarized noble gas (HNG) magnetic resonance (MR) imaging, the available polarization is independent of field strength and for large radiofrequency (rf) coils, such as those used chest body noise becomes primary source making signal-to-noise ratio (SNR) largely frequency at intermediate strengths (0.1-0.5 T). Furthermore, reduction in transverse relaxation time, T2, HNG lungs with increasing strength, results a decrease achievable SNR higher fields. this work, optimum MR imaging was...

Abstract The development of hybrid medical imaging scanners has allowed with different detection modalities at the same time, providing anatomical and functional information within physiological time course patient in position. Until now, acquisition proton MRI lung anatomy hyperpolarised gas function required separate breath‐hold examinations, meaning that images were not spatially registered or temporally synchronised. We demonstrate concurrent from two nuclei vivo . temporal spatial...

Abstract In this study, the signal‐to‐noise ratio of hyperpolarized 129 Xe human lung magnetic resonance imaging was compared at 1.5 T and 3 T. Experiments were performed both B 0 fields with quadrature double Helmholtz transmit–receive chest coils same geometry subject loads. Differences in sensitivity between two field strengths assessed from multi‐slice 2D ventilation images obtained a spatial resolution 15 mm × 4 mm. There systematically higher observed than by factor 1.25. Mean image...

To compare lobar lung ventilation computed from expiratory and inspiratory tomographic (CT) data with direct measurements of at hyperpolarized helium 3 ((3)He) magnetic resonance (MR) imaging by using same-breath hydrogen 1 ((1)H) MR examinations to coregister the multimodality images.The study was approved national research ethics committee, written patient consent obtained. Thirty patients asthma underwent breath-hold CT total capacity functional residual capacity. (3)He (1)H images were...

Abstract Purpose Hyperpolarized xenon MRI suffers from heterogeneous coil bias and magnetization decay that obscure pulmonary abnormalities. Non‐physiological signal variability can be mitigated by measuring mapping the nominal flip angle, rescaling images to correct for decay. While angle maps calculated sequentially acquired images, scan time breath‐hold duration are doubled. Here, we exploit low‐frequency oversampling of 2D‐spiral keyhole reconstruction measure a single acquisition....

Purpose To assess the magnitude of regional response to respiratory therapeutic agents in lungs by using treatment mapping (TRM) with hyperpolarized gas magnetic resonance (MR) imaging. TRM was used quantify physiologic adults asthma who underwent a bronchodilator challenge. Materials and Methods This study approved national research ethics committee performed informed consent. Imaging 20 adult patients helium 3 (3He) ventilation MR Two sets baseline images were acquired before inhalation...

Abstract Adding prior knowledge to compressed sensing reconstruction can improve image reconstruction. In this work, two approaches are investigated of two‐dimensional hyperpolarized 3 He lung ventilation images using knowledge. When compared against a standard reconstruction, the proposed methods allowed acquisition with higher under‐sampling factors and reduction blurring effects that increase when fixed flip angles used. These incorporate polarization decay mutual anatomical information...

Summary Background With increasing survival of patients with more severe forms congenital diaphragmatic hernia (CDH) and risk long‐term respiratory morbidity, studies on lung morphology are needed. We used hyperpolarised 3 He MRI anatomical 1 H in a cohort young adult CDH to image regional ventilation microstructure, focusing morphological micro‐structural (alveolar) abnormalities. Methods Nine left‐sided CDH, born 1975–1993, were studied. Regional was imaged MRI, the apparent diffusion...

The purpose of this work was to assess the reproducibility percentage ventilated lung volume (PV) measured from hyperpolarized (HP) 3 He and 1 H anatomical images acquired in same breath‐hold when compared with PV separate breath‐holds. Volumetric ventilation resolution were during breath‐hold. To reproducibility, procedure performed twice a short gap between acquisitions. In addition, also breath for comparison. ( divided by total volume) calculated using single‐breath‐hold (PV single )...

Lung pO2 mapping with (3)He MRI assumes that the sources of signal decay time during a breath-hold are radiofrequency depolarization and oxygen-dependent T1 relaxation, but method is sensitive to other spatio-temporal change such as diffusion. The purpose this work was assess use in patients chronic obstructive pulmonary disease.Ten moderate severe disease were scanned 3D single sequence.Images showed increasing over some lung regions due delayed ventilation breath-hold. Regions physically...

Hyperpolarized gas MRI generates highly detailed maps of lung ventilation and physiological function while CT provides corresponding anatomical structural information.Fusion such complementary images enables quantitative analysis pulmonary structure-function.However, direct image registration hyperpolarized to is problematic, particularly in lungs whose boundaries are difficult delineate due heterogeneity.This study presents a novel indirect method registering utilizing 1 H-structural MR...

Hyperpolarized noble gas (HNG) magnetic resonance (MR) imaging is a very promising noninvasive tool for the investigation of animal models lung disease, particularly to follow longitudinal changes in function and anatomy without accumulated radiation dose associated with x rays. The two most common gases this purpose are H3e (helium 3) X129e (xenon 129), latter providing cost-effective approach clinical applications. Hyperpolarization typically achieved using spin-exchange optical pumping...

Abstract Purpose To compare susceptibility effects in hyperpolarized 3 He lung MRI at the clinically relevant field strengths of 1.5T and 3T. Materials Methods Susceptibility‐related B 0 inhomogeneity was evaluated on a macroscopic scale by mapping via phase difference. Subpixel were quantified T . Comparison made between ventilation images obtained from same volunteers both strengths. Results The maps 3T show enhanced off‐resonance close to diaphragm ribs due differences. average voxel (20...

Abstract Parallel imaging presents a promising approach for MRI of hyperpolarized nuclei, as the penalty in signal‐to‐noise ratio typically encountered with 1 H due to reduction acquisition time can be offset by an increase flip angle. The generally exhibits strong dependence on angle, which makes homogeneous B + transmit field desirable. This paper flexible 32‐channel receive array 3 He human lung at 1.5T designed insertion into asymmetric birdcage coil. While allows parallel high...