Pulmonary MRI in Newborns and Children.

Lung MRI is an important tool in the assessment and monitoring of pediatric and neonatal lung disorders. MRI can provide both similar and complementary image contrast to computed tomography for imaging the lung macrostructure, and beyond this, a number of techniques have been developed for imaging the key functions of the lungs, namely ventilation, perfusion, and gas exchange, through the use of free-breathing proton and hyperpolarized gas MRI. Here, we review the state-of-the-art in MRI methods that have found utility in pediatric and neonatal lung imaging, the structural and physiological information that can be gleaned from such images, and strategies that have been developed to deal with respiratory (and cardiac) motion, and other technological challenges.

Clinical Outcomes Through Two Years for Infants With Bronchopulmonary Dysplasia and Tracheomalacia.

Background: Tracheomalacia (TM) is common in infants with bronchopulmonary dysplasia (BPD) and associated with respiratory morbidity. Assessment of TM was historically via bronchoscopy, but recent studies demonstrate that ultrashort echo-time (UTE) magnetic resonance imaging (MRI) can accurately assess TM in neonates.

Research Question: Do neonates with MRI-identified TM and BPD have increased respiratory morbidity through age 2 years?

Methods: We performed an observational cohort study of 54 subjects with BPD and assessed TM using UTE MRI at term-equivalent age.

Magnetic Resonance Imaging Assessment of Pulmonary Vascularity in Preterm Infants with Bronchopulmonary Dysplasia.

Introduction: Pulmonary hypertension often complicates bronchopulmonary dysplasia (BPD) and infants with BPD plus pulmonary hypertension experience higher mortality rates. Current methods to evaluate pulmonary hypertension fail to evaluate the primary cause of this disease. We hypothesize that preterm infants with BPD experience altered pulmonary vascular growth and that magnetic resonance imaging (MRI) can be used to assess vascularity in BPD.

Comparison of weighting algorithms to mitigate respiratory motion in free-breathing neonatal pulmonary radial UTE-MRI.

. Thoracoabdominal MRI is limited by respiratory motion, especially in populations who cannot perform breath-holds. One approach for reducing motion blurring in radially-acquired MRI is respiratory gating.

Tracheomalacia Reduces Aerosolized Drug Delivery to the Lung.

Neonates with respiratory issues are frequently treated with aerosolized medications to manage lung disease or facilitate airway clearance. Dynamic tracheal collapse (tracheomalacia [TM]) is a common comorbidity in these patients, but it is unknown whether the presence of TM alters the delivery of aerosolized drugs. To quantify the effect of neonatal TM on the delivery of aerosolized drugs.

Evaluation of regional lung mass and growth in neonates with bronchopulmonary dysplasia using ultrashort echo time magnetic resonance imaging.

Rationale: Bronchopulmonary dysplasia (BPD) is the most common long term pulmonary morbidity in premature infants and is characterized by impaired lung growth and development. We hypothesized that lung mass growth is a critical factor in determining outcomes in infants with BPD.

Objectives: To measure regional lung density and mass in infants with BPD and compare to clinical variables.

Initial feasibility and challenges of hyperpolarized Xe MRI in neonates with bronchopulmonary dysplasia.

Purpose: The underlying functional and microstructural lung disease in neonates who are born preterm (bronchopulmonary dysplasia, BPD) remains poorly characterized. Moreover, there is a lack of suitable techniques to reliably assess lung function in this population. Here, we report our preliminary experience with hyperpolarized Xe MRI in neonates with BPD.

Magnetic Resonance Imaging-Based Evaluation of Anatomy and Outcome Prediction in Infants with Esophageal Atresia.

Introduction: There is currently no validated diagnostic modality to characterize the anatomy and predict outcomes of tracheal esophageal defects, such as esophageal atresia (EA) and tracheal esophageal fistulas (TEFs). We hypothesized that ultra-short echo-time MRI would provide enhanced anatomic information allowing for evaluation of specific EA/TEF anatomy and identification of risk factors that predict outcome in infants with EA/TEF.

Methods: In this observational study, 11 infants had pre-repair ultra-short echo-time MRI of the chest completed.

Predicting tracheal work of breathing in neonates based on radiological and pulmonary measurements.

Tracheomalacia is an airway condition in which the trachea excessively collapses during breathing. Neonates diagnosed with tracheomalacia require more energy to breathe, and the effect of tracheomalacia can be quantified by assessing flow-resistive work of breathing (WOB) in the trachea using computational fluid dynamics (CFD) modeling of the airway. However, CFD simulations are computationally expensive; the ability to instead predict WOB based on more straightforward measures would provide a clinically useful estimate of tracheal disease severity.

Dynamic imaging using motion-compensated smoothness regularization on manifolds (MoCo-SToRM).

. We introduce an unsupervised motion-compensated reconstruction scheme for high-resolution free-breathing pulmonary magnetic resonance imaging..

Quantitative cardiopulmonary magnetic resonance imaging in neonatal congenital diaphragmatic hernia.

Background: Pulmonary arterial hypertension, impaired cardiac function and lung hypoplasia are common in infants with congenital diaphragmatic hernia (CDH) and are associated with increased morbidity and mortality. Robust noninvasive methods to quantify these abnormalities in early infancy are lacking.

Objective: To determine the feasibility of MRI to quantify cardiopulmonary hemodynamics and function in infants with CDH and to investigate left-right blood flow and lung volume discrepancies.

Bronchopulmonary dysplasia from chest radiographs to magnetic resonance imaging and computed tomography: adding value.

Bronchopulmonary dysplasia (BPD) is a common long-term complication of preterm birth. The chest radiograph appearance and survivability have evolved since the first description of BPD in 1967 because of improved ventilation and clinical strategies and the introduction of surfactant in the early 1990s. Contemporary imaging care is evolving with the recognition that comorbidities of tracheobronchomalacia and pulmonary hypertension have a great influence on outcomes and can be noninvasively evaluated with CT and MRI techniques, which provide a detailed evaluation of the lungs, trachea and to a lesser degree the heart.

Fetal lung development via quantitative biomarkers from diffusion MRI and histological validation in rhesus macaques.

Objective: To demonstrate sensitivity of diffusion-weighted MRI (DW-MRI) to pulmonary cellular-space changes during normal in utero development using fetal rhesus macaques, compared to histological biomarkers.

Study Design: In vivo/ex vivo DW-MRI was acquired in 26 fetal rhesus lungs (early-canalicular through saccular stages). Apparent diffusion coefficients (ADC) from MRI and tissue area density (H&E), alveolar type-II cells (ABCA3), and epithelial cells (TTF1) from histology were compared between gestational stages.

Case Report: Esophageal Bronchus in a Neonate, With Image, Histological, and Molecular Analysis.

In this case report, we describe the clinical course of a neonate who presented initially with respiratory distress and later with choking during feeding. He was subsequently found to have an esophageal bronchus to the right upper lung lobe, a rare communicating bronchopulmonary foregut malformation. Histological and molecular analysis of the fistula and distal tissues revealed that the proximal epithelium from the esophageal bronchus has characteristics of both esophageal and respiratory epithelia.

Neonates With Tracheomalacia Generate Auto-Positive End-Expiratory Pressure via Glottis Closure.

Background: In pediatrics, tracheomalacia is an airway condition that causes tracheal lumen collapse during breathing and may lead to the patient requiring respiratory support. Adult patients can narrow their glottis to self-generate positive end-expiratory pressure (PEEP) to raise the pressure in the trachea and prevent collapse. However, auto-PEEP has not been studied in newborns with tracheomalacia.

Modern pulmonary imaging of bronchopulmonary dysplasia.

Bronchopulmonary dysplasia (BPD) is a complex and serious cardiopulmonary morbidity in infants who are born preterm. Despite advances in clinical care, BPD remains a significant source of morbidity and mortality, due in large part to the increased survival of extremely preterm infants. There are few strong early prognostic indicators of BPD or its later outcomes, and evidence for the usage and timing of various interventions is minimal.

Effects of neonatal lung abnormalities on parenchymal R * estimates.

Infants admitted to the neonatal intensive care unit (NICU) often suffer from multifaceted pulmonary morbidities that are not well understood. Ultrashort echo time (UTE) magnetic resonance imaging (MRI) is a promising technique for pulmonary imaging in this population without requiring exposure to ionizing radiation. The aims of this study were to investigate the effect of neonatal pulmonary disease on R * and tissue density and to utilize numerical simulations to evaluate the effect of different alveolar structures on predicted R *.

Quantitative Evaluation of Subglottic Stenosis Using Ultrashort Echo Time MRI in a Rabbit Model.

Objective/hypothesis: To assess the ability of ultra-short echo time (UTE)-MRI to detect subglottic stenosis (SGS) and evaluate response to balloon dilation. To correlate measurements from UTE-MRI with endotracheal-tube (ETT)-sizing and to investigate whether SGS causes change in airway dynamics.

Study Design: Animal research study.

Subglottic Stenosis Position Affects Work of Breathing.

Objectives: Subglottic stenosis (SGS) is the most common type of laryngeal stenosis in neonates. SGS severity is currently graded based on percent area of obstruction (%AO) via the Myer-Cotton grading scale. However, patients with similar %AO can have widely different clinical courses.