helium-3-atom and Asthma

Hyperpolarized gas with helium (HHe-3) MR (magnetic resonance) is a noninvasive imaging method which maps and quantifies regions of ventilation heterogeneity (VH) in the lung. VH is an important feature of asthma, but little is known as to how VH informs patient phenotypes.. To determine if VH indicators quantified by HHe-3 MR imaging (MRI) predict phenotypic characteristics and map to regions of inflammation in children with problematic wheeze or asthma.. Sixty children with poorly-controlled wheeze or asthma underwent HHe-3 MRI, including 22 with bronchoalveolar lavage (BAL). The HHe-3 signal intensity defined four ventilation compartments. The non-ventilated and hypoventilated compartments divided by the total lung volume defined a VH index (VHI %).. Children with VHI % in the upper quartile had significantly greater airflow limitation, bronchodilator responsiveness, blood eosinophils, expired nitric oxide (FeNO), and BAL eosinophilic or neutrophilic granulocyte patterns compared to children with VHI % in the lower quartile. Lavage return from hypoventilated bronchial segments had greater eosinophil % than from ventilated segments.. In children with asthma, greater VHI % as measured by HHe-3 MRI identifies a severe phenotype with higher type 2 inflammatory markers, and maps to regions of lung eosinophilia. Listed on ClinicalTrials. gov (NCT02577497).

Topics: Asthma; Helium; Humans; Isotopes; Lung; Magnetic Resonance Imaging; Phenotype

Hyperpolarized helium 3 magnetic resonance imaging (. To evaluate the safety of. This was a retrospective observational study.. There were no serious adverse events, but three minor adverse events (2.3%; headache, dizziness and mild hypoxia) were reported. We found statistically significant increases in heart rate and SpO. The use of

Topics: Adolescent; Asthma; Child; Female; Helium; Humans; Isotopes; Lung; Magnetic Resonance Imaging; Male; Retrospective Studies

There is an unmet need for an objective biomarker to predict asthma exacerbations.. Our aim was to assess the ventilation defect percent (VDP) on hyperpolarized helium-3 magnetic resonance imaging as a predictor of exacerbation frequency following imaging.. Subjects underwent hyperpolarized helium-3 and conventional clinical measurements, including pulmonary function tests, during a period of disease stability, and exacerbations were recorded prospectively over the following 2 years. We used a Poisson regression tree model to estimate an optimal VDP threshold for classifying subjects into high- versus low-exacerbation groups and then used statistical regression to compare this VDP threshold against conventional clinical measures as predictors of exacerbations.. A total of 67 individuals with asthma (27 males and 40 females, 28 with mild-to-moderate asthma and 39 with severe asthma) had a median VDP of 3.75% (1.2% [first quartile]-7.9% [third quartile]). An optimal VDP threshold of 4.28% was selected on the basis of the maximum likelihood estimation of the regression tree model. Subjects with a VDP greater than 4.28% (n = 32) had a median of 1.5 exacerbations versus 0.0 for subjects with a VDP less than 4.28% (n = 35). In a stepwise multivariate regression model, a VDP greater than 4.28% was associated with an exacerbation incidence rate ratio of 2.5 (95% CI = 1.3-4.7) versus a VDP less than or equal to 4.28%. However, once individual medical history was included in the model, VDP was no longer significant. Nonetheless, VDP may provide an objective and complementary quantitative marker of individual exacerbation risk that is useful for monitoring individual change in disease status, selecting patients for therapy, and assessing treatment response.. VDP measured with magnetic resonance imaging shows promise as a biomarker of prospective asthma exacerbations.

Topics: Adult; Asthma; Biomarkers; Disease Progression; Female; Follow-Up Studies; Helium; Humans; Isotopes; Lung; Magnetic Resonance Imaging; Male; Middle Aged; Prognosis; Respiratory Function Tests; Severity of Illness Index; Young Adult

Recent pulmonary functional MRI findings of spatially and temporally persistent ventilation abnormalities in patients with asthma contrast with previous in silico modeling studies that suggest that in asthma, ventilation defects may be randomly distributed. In a case study that used pulmonary MRI, CT imaging, and pulmonary function tests, we prospectively evaluated over the course of 7 years, nonidentical female adult twins, each with a lifelong history of asthma. We evaluated pulmonary function and MRI ventilation heterogeneity at baseline and follow-up after 7 years. In both twins, there was a spatially identical MRI ventilation defect and an abnormal subsegmental left-sided upper lobe airway that persisted in the same spatial location after 7 years. If ventilation defects are randomly distributed, this bears a probability of approximately one per 130,000 people. Our MRI observations in related patients with asthma suggest that ventilation abnormalities may not be randomly distributed in patients with asthma and persist distal to airway abnormalities for long periods of time.

Topics: Airway Remodeling; Asthma; Bronchi; Female; Forced Expiratory Volume; Helium; Humans; Isotopes; Lung; Magnetic Resonance Imaging; Middle Aged; Pulmonary Ventilation; Respiratory Function Tests; Tomography, X-Ray Computed; Twins, Dizygotic

Image registration of lung CT images acquired at different inflation levels has been proposed as a surrogate method to map lung 'ventilation'. Prior to clinical use, it is important to understand how this technique compares with direct ventilation imaging modalities such as hyperpolarised gas MRI. However, variations in lung inflation level have been shown to affect regional ventilation distributions. Therefore, the aim of this study was to evaluate the impact of lung inflation levels when comparing CT ventilation imaging to ventilation from

Topics: Adult; Algorithms; Asthma; Breath Holding; Female; Helium; Humans; Hydrogen; Image Processing, Computer-Assisted; Isotopes; Lung; Magnetic Resonance Imaging; Male; Middle Aged; Pulmonary Ventilation; Respiration; Time Factors; Tomography, X-Ray Computed

Background Longitudinal progression to irreversible airflow limitation occurs in approximately 10% of patients with asthma, but it is difficult to identify patients who are at risk for this transition. Purpose To investigate 6-year longitudinal changes in hyperpolarized helium 3 (

Topics: Adult; Asthma; Bronchial Provocation Tests; Bronchodilator Agents; Female; Follow-Up Studies; Helium; Humans; Isotopes; Longitudinal Studies; Lung; Magnetic Resonance Imaging; Male; Middle Aged; Predictive Value of Tests

Topics: Asthma; Female; Helium; Humans; Isotopes; Lung; Magnetic Resonance Imaging; Male; Pulmonary Ventilation

To determine lobar ventilation patterns in asthmatic lungs with hyperpolarized. Eighty-two subjects (14 normal, 48 mild-to-moderate asthma, and 20 severe asthma) underwent HP. In mild-to-moderate asthma, the RML and RUL showed significantly greater VDP than the two lower lobes (RLL and LLL) (P ≤ .047). In severe asthma, the pattern was more variable with the VDP in the RUL significantly greater than in the RLL (P = .026). In both asthma groups, the lower lobes (RLL and LLL) showed significantly higher high ventilation percent and Hs compared to the three upper lobes (all P ≤ .015).. In asthma, the RML and RUL showed greater ventilation abnormalities, and the RLL and LLL were more highly ventilated with greater local heterogeneity. These findings may facilitate guided bronchoscopic sampling and localized airway treatment in future studies.

Topics: Adolescent; Adult; Asthma; Female; Helium; Humans; Isotopes; Lung; Magnetic Resonance Imaging; Male; Middle Aged; Pulmonary Ventilation; Severity of Illness Index; Tomography, X-Ray Computed; Young Adult