Magentic Resonance Imaging Evaluation of Regional Lung Vts in Severe Neonatal Bronchopulmonary Dysplasia.
Am J Respir Crit Care Med
; 202(7): 1024-1031, 2020 10 01.
Article
em En
| MEDLINE
| ID: mdl-32459506
ABSTRACT
Rationale Bronchopulmonary dysplasia is a heterogeneous lung disease characterized by regions of cysts and fibrosis, but methods for evaluating lung function are limited to whole lung rather than specific regions of interest.Objectives:
Respiratory-gated, ultrashort echo time magnetic resonance imaging was used to test the hypothesis that cystic regions of the lung will exhibit a quantifiable Vt that will correlate with ventilator settings and clinical outcomes.Methods:
Magnetic resonance images of 17 nonsedated, quiet-breathing infants with severe bronchopulmonary dysplasia were reconstructed into end-inspiration and end-expiration images. Cysts were identified and measured by using density threshold combined with manual identification and segmentation. Regional Vts were calculated by subtracting end-expiration from end-inspiration volumes in total lung, noncystic lung, total-cystic lung, and individual large cysts.Measurements and MainResults:
Cystic lung areas averaged larger Vts than noncystic lung when normalized by volume (0.8 ml Vt/ml lung vs. 0.1 ml Vt/ml lung, P < 0.002). Cyst Vt correlates with cyst size (P = 0.012 for total lung cyst and P < 0.002 for large cysts), although there was variability between individual cyst Vt, with 22% of cysts demonstrating negative Vt. Peak inspiratory pressure positively correlated with total lung Vt (P = 0.027) and noncystic Vt (P = 0.015) but not total lung cyst Vt (P = 0.8). Inspiratory time and respiratory rate did not improve Vt of any analyzed lung region.Conclusions:
Cystic lung has greater normalized Vt when compared with noncystic lung. Ventilator pressure increases noncystic lung Vt, but inspiratory time does not correlate with Vt of normal or cystic lung.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Respiração Artificial
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Displasia Broncopulmonar
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Imageamento por Ressonância Magnética
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Volume de Ventilação Pulmonar
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Cistos
Tipo de estudo:
Guideline
Limite:
Female
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Humans
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Infant
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Male
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Newborn
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article