Dataset Information

Alveolarization continues during childhood and adolescence: new evidence from helium-3 magnetic resonance.

ABSTRACT:

Rationale

The current hypothesis that human pulmonary alveolarization is complete by 3 years is contradicted by new evidence of alveolarization throughout adolescence in mammals.

Objectives

We reexamined the current hypothesis using helium-3 ((3)He) magnetic resonance (MR) to assess alveolar size noninvasively between 7 and 21 years, during which lung volume nearly quadruples. If new alveolarization does not occur, alveolar size should increase to the same extent.

Methods

Lung volumes were measured by spirometry and plethysmography in 109 healthy subjects aged 7-21 years. Using (3)HeMR we determined two independent measures of peripheral airspace dimensions: apparent diffusion coefficient (ADC) of (3)He at FRC (n = 109), and average diffusion distance of helium (X(rms)) by q-space analysis (n = 46). We compared the change in these parameters with lung growth against a model of lung expansion with no new alveolarization.

Measurements and main results

ADC increased by 0.19% for every 1% increment in FRC (95% confidence interval [CI], 0.13-0.25), whereas the expected change in the absence of neoalveolarization is 0.41% (95% CI, 0.31-0.52). Similarly, increase of (X(rms)) with FRC was significantly less than the predicted increase in the absence of neoalveolarization. The number of alveoli is estimated to increase 1.94-fold (95% CI, 1.64-2.30) across the age range studied.

Conclusions

Our observations are best explained by postulating that the lungs grow partly by neoalveolarization throughout childhood and adolescence. This has important implications: developing lungs have the potential to recover from early life insults and respond to emerging alveolar therapies. Conversely, drugs, diseases, or environmental exposures could adversely affect alveolarization throughout childhood.

SUBMITTER: Narayanan M

PROVIDER: S-EPMC3410735 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature

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Publications

Alveolarization continues during childhood and adolescence: new evidence from helium-3 magnetic resonance.

Narayanan Manjith M Owers-Bradley John J Beardsmore Caroline S CS Mada Marius M Ball Iain I Garipov Ruslan R Panesar Kuldeep S KS Kuehni Claudia E CE Spycher Ben D BD Williams Sian E SE Silverman Michael M

American journal of respiratory and critical care medicine 20111027 2

<h4>Rationale</h4>The current hypothesis that human pulmonary alveolarization is complete by 3 years is contradicted by new evidence of alveolarization throughout adolescence in mammals.<h4>Objectives</h4>We reexamined the current hypothesis using helium-3 ((3)He) magnetic resonance (MR) to assess alveolar size noninvasively between 7 and 21 years, during which lung volume nearly quadruples. If new alveolarization does not occur, alveolar size should increase to the same extent.<h4>Methods</h4>L ...[more]

PMID: 22071328

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Dataset Information

Alveolarization continues during childhood and adolescence: new evidence from helium-3 magnetic resonance.

Rationale

Objectives

Methods

Measurements and main results

Conclusions

Publications

Alveolarization continues during childhood and adolescence: new evidence from helium-3 magnetic resonance.

Similar Datasets

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